Global and national trends in childhood vaccination coverage from 1980 to 2023 with forecasts to 2030

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However, more recent decades have seen persistent coverage inequities and stagnating progress, which have been further amplified by the COVID-19 pandemic. In 2019, WHO set ambitious goals for improving vaccine coverage globally through the Immunization Agenda 2030 (IA2030). Now halfway through the decade, understanding past and recent coverage trends can help inform and reorient strategies for approaching these aims in the next 5 years. Methods Based on the Global Burden of Diseases, Injuries, and Risk Factors Study 2023, this study provides updated global, regional, and national estimates of routine childhood vaccine coverage from 1980 to 2023 for 204 countries and territories for 11 vaccine-dose combinations recommended by WHO for all children globally. Employing advanced modeling techniques, this analysis accounts for data biases and heterogeneity and integrates new methodologies to model vaccine scale-up and COVID-19 pandemic-related disruptions. To contextualize historic coverage trends and gains still needed to achieve the IA2030 coverage targets, we supplement these results with several secondary analyses: (1) we assess the effect of the COVID-19 pandemic on vaccine coverage; (2) we forecast coverage of select life-course vaccines up to 2030; and (3) we analyze progress needed to reduce the number of zero-dose children by half between 2023 and 2030. Findings Overall, global coverage for the original EPI vaccines against diphtheria, tetanus, and pertussis (first dose [DTP1] and third dose [DTP3]), measles (MCV1), polio (Pol3), and tuberculosis (BCG) nearly doubled from 1980 to 2023. However, this long-term trend masks recent challenges. Coverage gains slowed between 2010 and 2019 in many countries and territories, including declines in 21 of 36 high-income countries and territories for at least one of these vaccine doses (excluding BCG, which has been removed from routine immunization schedules in some countries and territories). The COVID-19 pandemic exacerbated these challenges, with global rates for these vaccines declining sharply since 2020, and still not returning to pre-COVID-19 pandemic levels as of 2023. Coverage for newer vaccines developed and introduced in more recent years, such as immunizations against pneumococcal disease (PCV3) and rotavirus (complete series; RotaC) and a second dose of the measles vaccine (MCV2), saw continued increases globally during the COVID-19 pandemic due to ongoing introductions and scale-ups, but at slower rates than expected in the absence of the pandemic. Forecasts to 2030 for DTP3, PCV3, and MCV2 suggest that only DTP3 would reach the IA2030 target of 90% global coverage, and only under an optimistic scenario. The number of zero-dose children, proxied as children younger than 1 year who do not receive DTP1, decreased by 74·9% (95% uncertainty interval 72·1–77·3) globally between 1980 and 2019, with most of those declines reached during the 1980s and the 2000s. After 2019, counts of zero-dose children rose to a COVID 19-era peak of 18·6 million (17·6–20·0) in 2021. Most zero-dose children remain concentrated in conflict-affected regions and those with various constraints on resources available to put towards vaccination services, particularly sub-Saharan Africa. As of 2023, more than 50% of the 15·7 million (14·6–17·0) global zero-dose children resided in just eight countries (Nigeria, India, Democratic Republic of the Congo, Ethiopia, Somalia, Sudan, Indonesia, and Brazil), emphasizing persistent inequities. Interpretation Our estimates of current vaccine coverage and forecasts to 2030 suggest that achieving IA2030 targets, such as halving zero-dose children compared with 2019 levels and reaching 90% global coverage for life-course vaccines DTP3, PCV3, and MCV2, will require accelerated progress. Substantial increases in coverage are necessary in many countries and territories, with those in sub-Saharan Africa and south Asia facing the greatest challenges. Recent declines will need to be reversed to restore previous coverage levels in Latin America and the Caribbean, especially for DTP1, DTP3, and Pol3. These findings underscore the crucial need for targeted, equitable immunisation strategies. Strengthening primary health-care systems, addressing vaccine misinformation and hesitancy, and adapting to local contexts are essential to advancing coverage. COVID-19 pandemic recovery efforts, such as WHO's Big Catch-Up, as well as efforts to bolster routine services must prioritize reaching marginalized populations and target subnational geographies to regain lost ground and achieve global immunisation goals. Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Introduction Building on the success of the global campaign to eradicate smallpox, the Expanded Programme on Immunisation (EPI) was launched in 1974 by WHO to extend the benefits of universal immunisation against common childhood diseases worldwide.1 EPI initially supported the deployment of vaccines to combat diphtheria, tetanus, pertussis, polio, measles, and tuberculosis. Over the ensuing 50 years, EPI—now renamed the Essential Programme on Immunization—has added more childhood vaccinations, recommending vaccinations for all children globally against hepatitis B, Haemophilus influenzae type b, pneumococcus, rotavirus, and rubella, along with a second dose of the measles vaccine, while broadening to include recommendations for adolescent vaccination against human papillomavirus.2 Through partnerships between local health-care workers, national immunisation programmes, regional authorities, and international organisations, EPI has achieved remarkable health gains. The effect of making routine childhood immunisation (ie, regular and ongoing immunisation services, often delivered during routine health visits) widely available has been drastic, resulting in an estimated 154 million deaths averted globally between 1974 and 2024, with nearly 95% of those in children younger than 5 years.3 Although delivering routine childhood vaccinations worldwide requires a tremendous investment of global resources, including approximately US $ 3·9 billion in development assistance for health in 2023,4 childhood immunisation has proven to be one of the most successful and cost-effective public health strategies known, both in terms of lives saved and return on investment.5, 6 Estimates have shown the financial rate of return to be in some instances up to 44-times the cost of vaccination.7 Yet the remarkable successes of EPI have slowed in the past decade and in some cases reversed, suggesting weaknesses in health services that were further exposed during the global upheaval caused by the COVID-19 pandemic, including social distancing measures, health system diversions, and supply chain disruptions. Previous estimates suggest that coverage with the third dose of the diphtheria, tetanus, and pertussis vaccine (DTP3) decreased in 94 countries and territories between 2010 and 2019, and only 11 countries worldwide were estimated to have reached the 2019 target set by the WHO Global Vaccine Action Plan of at least 90% coverage for all assessed vaccines.8 As coverage has stalled, new and increased outbreaks of vaccine-preventable illness, such as measles, polio, and diphtheria, have emerged in many countries and territories.9 To successfully further the reach, equity, and sustainability of global immunisation systems, it is necessary to overcome enduring and emerging challenges, such as growing economic uncertainty and geopolitical instability that constrain funding for vaccination and global health, migration, and population displacement,10, 11 geographical and sociodemographic disparities in access to vaccines,12, 13, 14, 15, 16, 17 disruptions to immunisation delivery related to events such as natural disasters or widespread infectious disease outbreaks such as those caused by the SARS-CoV-2 and Ebola viruses,18, 19, 20, 21, 22 and an upsurge in vaccine misinformation and hesitancy as detailed by the Vaccine Confidence Project.23, 24 To meet these challenges, WHO's World Health Assembly endorsed Immunization Agenda 2030 (IA2030),10 an updated framework to envision and achieve universal immunisation, building on the previous Global Vaccine Action Plan approach with a broader scope and increased tailoring for local contexts.25 Focused on centring the expertise of local and country-level partners and authorities,26 aligned with the UN's Sustainable Development Goal 3 to ensure healthy lives and promote wellbeing for all at all ages,27 IA2030 sets an ambitious global agenda to achieve “a world where everyone, everywhere, at every age, fully benefits from vaccines to improve health and well-being”.28 One of IA2030's primary goals is to promote equity by halving (relative to 2019) the number of zero-dose children, that is, children missed by routine childhood vaccination, typically proxied by estimating those who have not received any DTP doses. Zero-dose children are more likely to miss out on subsequent vaccinations29 and experience other types of deprivation,17 and strategies to reach these missed children with vaccination services can bolster routine health services more broadly. IA2030 further emphasises the necessity of extending the benefits of vaccination throughout the life course, reaching beyond early childhood to deliver essential catch-up vaccinations and booster doses, along with a growing number of new vaccines scheduled for administration after childhood. To this end, IA2030 sets a goal of achieving 90% global coverage for vaccines across the life course, including DTP3, the third dose of a pneumococcal conjugate vaccine (PCV3), the second dose of a measles-containing vaccine (MCV2), and the complete human papillomavirus vaccine series (HPVc).10, 28 These ambitious targets are important to prevent the resurgence of vaccine-preventable diseases and to foster strong and resilient immunisation and health-care systems that will serve as a platform for the introduction of new vaccines. The need for strong routine health systems to enable vaccine delivery was underscored during the pandemic and holds true today as new vaccines for malaria, dengue, Ebola virus, and other diseases are being developed and deployed. To advance universal childhood immunisation, a core principle of IA2030 is reliance on high-quality, targeted data to guide immunisation policies and programmes and to better measure progress extending vaccination coverage. Since 2000, a key source of vaccination data has been the WHO–UNICEF Estimates of National Immunization Coverage (WUENIC),30 which uses a rules-based approach to provide annual routine vaccination coverage estimates for all WHO member states using expert judgement and qualitative knowledge to compile primary data from available sources. WUENIC estimates use country-reported and administrative data gathered through the WHO–UNICEF Joint Reporting Form (JRF)30, 31, 32 and are informed by data from established household surveys, such as the Demographic and Health Surveys (DHS) Program and the Multiple Indicator Cluster Surveys. These estimates from WUENIC incorporate expert judgement and qualitative knowledge in their comprehensive compilation of primary data sources; however, the rules-based approach might lead to flat or noisy time trends, particularly in data-sparse locations, and is not able to account for uncertainty in the estimation process.32 Previous work from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) has applied a comprehensive statistical model to these data to systematically generate national estimates of vaccine coverage from 1980 to 2019.8 Because primary vaccination data can be inconsistent (ie, discrepant sampling methods and/or results),33 sparse (ie, few data in specific locations), and subject to bias (ie, systematic error imposed through biased sampling methodology),34, 35 the use of a statistical model to derive coverage estimates confers multiple advantages. These include the capacity to synthesise data from heterogeneous sources while accounting for the effects of discrepant data quality and types (eg, administrative vs survey) as well as the presence of systematic bias; to overcome data sparsity by leveraging time trends and other predictors; and to formally quantify estimation uncertainty. Here, following the 50th anniversary year of EPI's founding and halfway through the decade of IA2030, we build on the framework of the previous GBD vaccine coverage study8 to generate updated estimates of vaccine coverage for 204 countries and territories from 1980 to 2023. We analyse progress over time in the coverage of key childhood vaccine-dose combinations and estimate trends in numbers of zero-dose individuals. We extend the previous GBD analysis to include the COVID-19 era, including many data sources delayed in reporting by the COVID-19 pandemic. We deploy new methods to account for the immediate and enduring effects of the COVID-19 pandemic in a unified framework, enhance estimation of the scale-up of newly introduced vaccines, and improve our estimation of counts of zero-dose children by modeling the first dose of the diphtheria, tetanus, and pertussis vaccine (DTP1) directly. Looking forward, we assess progress towards the IA2030 goals of 50% reduction in zero-dose children and 90% global coverage of select life-course vaccines in secondary analyses. First, building off an early framework developed by Causey and colleagues,18 we use a counterfactual approach to quantify the effect of the COVID-19 pandemic on the number of children who missed routine vaccinations between 2020 and 2023. Second, we evaluate progress needed to reach a 50% reduction in zero-dose children by 2030. Last, we forecast future DTP3, PCV3, and MCV2 coverage up to 2030 under three scenarios to show the range of plausible future trajectories. These comprehensive, updated estimates show progress and challenges in the effort to immunize against routine childhood diseases, providing crucial evidence to inform policies, programs, and investments aimed at ensuring that all children, everywhere, receive life-saving vaccinations. This manuscript was produced as part of the GBD Collaborator Network and in accordance with the GBD Protocol.36 Because newly available data and modified methods were used to update the full time series of estimates from 1980 to 2023, these results supersede all previous estimates. Methods Overview To generate coverage estimates of routine childhood vaccination in 204 countries and territories from 1980 to 2023, our core analysis followed the previous GBD methods,8 applying a multistep modelling approach using spatiotemporal Gaussian process regression (ST-GPR)37 and meta-regression—Bayesian, regularised, trimmed (MR-BRT)38 tools to synthesise data collected primarily through the WHO–UNICEF JRF31 and through household surveys. Annual country-specific coverage estimates were calculated for 11 childhood vaccine-dose combinations supported by EPI and administered via routine national immunisation programmes, including five vaccine-dose combinations from the four vaccines introduced in 1974 against diphtheria, tetanus, and pertussis (DTP1 and DTP3), measles (first dose of a measles-containing vaccine [MCV1]), polio (third dose of any form of polio vaccination [Pol3]), and tuberculosis (BCG)—plus six vaccine-dose combinations rolled out in subsequent years (newer vaccines) targeting hepatitis B (third dose [HepB3]), Haemophilus influenzae type b (third dose [Hib3]), rotavirus (complete series; RotaC), pneumococcus (PCV3), rubella (first dose of a rubella-containing vaccine [RCV1]), and measles (MCV2). Our core model adjusted for location-varying and time-varying bias in country-reported data from the JRF; leveraged data-dense evidence for specific locations, years, and vaccines to estimate coverage in instances of data sparsity; accounted for vaccine disruptions and country-specific years of vaccine introduction; and propagated uncertainty. Details regarding our innovations to the previous GBD methods and novel secondary analyses are provided in the sections below. This study complies with the Guidelines for Accurate and Transparent Health Estimates Reporting (GATHER) statement39. Analyses were done with R version 4.4.0. Statistical code used for estimation is publicly available on the Global Health Data Exchange.40 Data We reviewed 8042 data sources between 1980 and 2023, of which 1085 unique sources were included in the analysis (representing 128 new sources compared with the previous GBD vaccine coverage study,8 including 37 new sources from 2020 to 2023 and 91 from 2019 and earlier). These sources comprise 64 546 country-year-vaccine-dose-specific datapoints, including 14 700 datapoints from vaccination-related household surveys (eg, DHS, Multiple Indicator Cluster Surveys, and other multicountry and country-specific surveys), 49 800 datapoints from administrative and official country-reported vaccine coverage data from the JRF and other sources, and supplemental data regarding stockout events, vaccine introductions to national immunisation programmes, and vaccine schedules, also reported through the JRF.41, 42, 43, 44 Data were catalogued and are publicly available on the Global Health Data Exchange.40 As in the previous study,8 we grouped coverage data by birth cohort (12–23 months, 24–35 months, 36–47 months, 48–59 months—excluding cohorts younger than 1 year at the time of the survey) and—to align survey-based data with country-reported data—used county-specific vaccine schedules and vaccine introduction years to assign each cohort to the year of expected vaccine delivery. Modelling of administrative data bias To account for bias in country-reported coverage data,45 as in the GBD 2020 study, we used the MR-BRT modelling framework to assess differences in coverage within paired observations of survey data and original country-reported coverage from the same country-years. This bias was modelled as the ratio of survey data coverage to country-reported coverage, adjusting for the Healthcare Access and Quality (HAQ) Index (a composite index designed to assess and compare health-care access and quality),46 with the expectation that bias in reporting might vary based on the quality of health-care services. These MR-BRT bias predictions then served as a first-stage input for ST-GPR models. These bias adjustments were only applied directly for the original EPI vaccines; estimates for newer vaccines leveraged bias adjustments for the original EPI comparator vaccines through the ratio modelling process. New for this study, bias was directly modelled for both DTP1 and DTP3, rather than DTP3 only. Modelling of stockouts and other disruptions to vaccine coverage, including COVID-19 To account for acute temporal disruptions (ie, drops) in coverage due to stockouts or other isolated events, we first modelled the magnitude of disruptions for vaccine-country-years with reported stockout events reported via the JRF42 or other identified disruption events. Disruption magnitudes were then included as a covariate in vaccine coverage modelling. New in this study, this covariate was devised by calculating the difference in coverage between country-reported data in vaccine-country-years identified as experiencing disruptions and counterfactual coverage estimates from models that excluded these vaccine-country-years. To account for disruptions due to COVID-19, also new to this study, we considered all vaccine-country-years for 2020 to 2023 as candidates for disruption events. New in this study, for vaccine-country-years in this period without available country-reported data, we imputed disruption magnitudes based on vaccine-year-specific distributions from locations with data. Vaccine coverage model Our core analysis relied on modelling in ST-GPR to implement a multistep approach that produced location-specific annual estimates of vaccine coverage for 11 routine childhood vaccine-dose combinations in 204 countries and territories over the period of 1980 to 2023. ST-GPR is a stochastic modelling tool designed to synthesise heterogeneous inputs and flexibly smooth data over space and time, leveraging available high-density data to guide predictions in cases of absent or sparse data and to minimise prediction error.37 The model uses a three-stage approach, starting first with a regression incorporating covariates that might affect vaccine coverage. The second stage implements spatiotemporal smoothing, and the final stage uses a Gaussian Process regression to reduce error around high-precision data. Improvements to this study include modifications to the modelling strategy for DTP. In previous GBD cycles, DTP3 coverage was modelled directly, and DTP1 was estimated with a continuation ratio ordinal regression approach.8 For GBD 2023, with increasing global focus on zero-dose children (proxied as those who have not received DTP1), we now model DTP1 directly and, to ensure internal consistency where DTP1 must be greater than DTP3, estimate DTP3 by modelling the DTP3/DTP1 ratio. For the directly modelled vaccines—DTP1, MCV1, Pol3, and BCG—country-specific and year-specific estimates of coverage were produced using ST-GPR models fit to bias-adjusted official country-reported data and survey data. ST-GPR models included covariates for the HAQ Index;46 mortality rates due directly to war and terror events as per data from Armed Conflict Location and Event Data, Uppsala Conflict Data Program, and Ethiopia's Tigray War data; and vaccine disruptions. We also used this approach to model the ratio of DTP3/DTP1 coverage (using bias-adjusted official country-reported data and survey for both numerator and denominator), which was multiplied post-hoc by our modelled estimates of DTP1 coverage by draw to calculate DTP3 coverage. For other vaccines, we modelled the ratio of coverage to that of one of the original EPI vaccines, using ST-GPR to allow for similarities and differences in these relationships across space and time. DTP3 served as the denominator, or reference vaccine, for modelling HepB3, Hib3, PCV3, and RotaC vaccine coverage ratios, given that it is typically given either as part of a combination vaccine and/or on the same schedule as these vaccines, whereas MCV1 was used as the reference vaccine for MCV2 and RCV1, to ensure that MCV2 coverage does not exceed MCV1 coverage, and because RCV1 is often delivered in a combination vaccine with MCV1. All ratios were constrained to be less than one, assuming newer vaccine coverage will be less than the original corresponding reference vaccine. New for GBD 2023, we estimated the scale-up of each newer vaccine ratio as a function of years since introduction. By explicitly modelling scale-up patterns and allowing these to vary by country and vaccine, we improved estimation in early years after introduction and in settings with sparse data. We fit predictive spline models of coverage ratios using MR-BRT in a geographical cascade: vaccine-specific models were first fit across all countries and territories, and the global model fits then served as priors for country-specific models. In this process, coverage ratios were modelled as a function of vaccine disruptions, years-since-introduction (fit using a spline), and a country-level random effect. The results of these spline models were used as first-stage estimates in subsequent ST-GPR coverage ratio models. Last, we multiplied the predicted coverage ratios from ST-GPR by the corresponding reference vaccine coverage to generate final estimates of coverage. Uncertainty was propagated by sampling 1000 random draws from the posterior distribution of each modelling step and conducting all subsequent calculations by draw. Results were summarised using the mean of all draws and the ordinal 2·5th and 97·5th percentile of draws to compute 95% uncertainty intervals (UIs). Super-regional and global aggregate estimates were calculated at the draw level as target population-weighted means.47, 48 In-sample and out-of-sample goodness of fit statistics were calculated. Coverage estimates were also compared with estimates from the previous GBD 2020 vaccine coverage study and estimates published by WUENIC in 2024.8, 49 Secondary and post-hoc analyses To understand the effect of the COVID-19 pandemic on childhood vaccination rates, we calculated vaccine coverage in a counterfactual (ie, alternative) scenario in which coverage was not affected by disruptions due to COVID-19 (COVID-free). This was done by removing post-hoc the disruption covariate effects from coverage estimates in 2020–23. To account for potential disruptions that would have occurred even without the COVID-19 pandemic, we applied an adjustment scalar to the counterfactual estimates based on country-draw-level averages of disruption sizes for the preceding 5 years. This year range was chosen to reflect the most recent patterns in the occurrence and magnitude of disruptions. To assess progress towards the IA2030 goal of reducing the number of zero-dose children globally by half by 2030, compared with 2019, we considered a hypothetical scenario where all countries and territories reduce zero-dose children by 50% between these years (ie, equal contributions towards this goal). Using GBD population forecasts,50 we calculated the number of zero-dose children needed to be reached by 2030 and corresponding DTP1 coverage. To contextualise required DTP1 coverage increases, we calculated the 2023–30 annualised rate of change (AROC) in DTP1 coverage needed for each country to meet this target. We then compared these to the distribution of AROCs across historical 7-year periods from 2000 to 2019 for all countries and territories. To predict progress towards IA2030's target of 90% coverage in 2030 for routine childhood vaccination across the life course, we adapted methods of Foreman and colleagues51 and GBD 2021 Forecasting Collaborators52 to forecast future coverage for DTP3, PCV3, and MCV2. We produced reference vaccine coverage forecasts for 2030 that capture the most likely reference future scenario. Forecasted DTP3 coverage for the reference scenario was estimated in a predictive modelling framework that leverages historic relationships between vaccine coverage estimates and the Socio-demographic Index (SDI), a composite indicator measuring a country's development status, with a logistic regression framework with SDI as the sole covariate.48 To show a plausible range of future coverage trajectories, we also produced alternative better and worse scenario forecasts based on historic rates of change. The better and worse scenario estimates were forecasts based on the 85th and 15th percentiles, respectively, of the distribution of past rates of change in coverage (in natural log space) between subsequent years. The historic distributions were calculated by draw, pulling from across countries and territories and all year pairs between 1980 and 2019, excluding years affected by the COVID-19 pandemic. Rates of change from more recent years were weighted more heavily in the distribution compared with those from earlier in the time series. Forecasts of PCV3/DTP3 and MCV2/MCV1 coverage ratios were produced using equivalent ratio modelling techniques as used in historical coverage estimation. We then multiplied by forecasted DTP3 and MCV1 estimates, respectively, for each scenario to calculate PCV3 and MCV2 coverage. Results Trends in vaccine coverage, 1980–2019 Between 1980 and 2019, global vaccine coverage for the original EPI vaccines—BCG, MCV1, DTP1, DTP3, and Pol3—approximately doubled, from 38·1% (95% UI 33·9–42·3) in 1980 to 83·3% (82·7–84·0) in 2019 for BCG, 37·1% (32·3–41·6) to 83·1% (81·8–84·3) for MCV1, 48·8% (44·1–53·5) to 89·0% (88·3–89·6) for DTP1, 39·6% (34·8–44·3) to 80·9% (79·9–81·9) for DTP3, and 42·4% (38·8–46·4) to 79·6% (78·3–81·0) for Pol3. Across this timeframe, this equates to an estimated 4·1 billion (4·07–4·12) children vaccinated with BCG, 4·01 billion (3·98–4·04) with MCV1, 4·48 billion (4·45–4·51) with DTP1, 3·89 billion (3·85–3·93) with DTP3, and 4·00 billion (3·96–4·04) with Pol3 through routine immunization programs. However, these gains slowed or reversed between 2010 and 2019, even before COVID-19 pandemic-related disruptions in subsequent years. For MCV1, coverage declined between 2010 and 2019 for 100 of 204 countries and territories, with the biggest decrease in the Latin America and the Caribbean super-region (90·4% [88·6–91·9] in 2010; 86·8% [85·0–88·4] in 2019). For DTP1, DTP3, and Pol3, coverage declined between 2010 and 2019 for 100, 98, and 107 countries and territories, respectively, with the largest decreases similarly in Latin America and the Caribbean (DTP1 96·5% [96·0–96·9] in 2010 and 85·4% [83·3–87·3] in 2019; DTP3 89·8% [89·0–90·6] in 2010 and 73·9% [70·9–76·3] in 2019; Pol3 87·8% [86·9–88·7] in 2010 and 76·9% [74·9–78·6] in 2019). Of 158 countries and territories with BCG in the national immunisation schedule for all years between 2010 and 2019,41 coverage declined for 88 countries and territories over this period. For newer vaccines, coverage gains were more consistent. Coverage for HepB3 (80·1% [95% UI 79·0–81·0]), Hib3 (70·7% [69·6–71·7]), MCV2 (67·9% [66·7–69·2]), and RCV1 (69·0% [68·0–69·9]) had begun to approach that of the original EPI vaccines by 2019 (Fig. 1 ). Global expansion of coverage for PCV3 and RotaC did not begin until the mid-2000s, but by 2019 global coverage reached 48·1% (47·3–49·0) for PCV3 and 38·8% (38·2–39·5) for RotaC. Trends in zero-dose children, 1980–2019 Between 1980 and 2019, the global number of zero-dose children—as represented by children younger than 1 year who have not received a DTP1 dose—decreased by an estimated 74·9% (95% UI 72·1–77·3), from 58·8 million (53·4–64·2) to 14·7 million (13·8–15·6; Fig. 2 ). Most of these decreases occurred at the beginning of EPI from 1980 to 1990, when zero-dose counts decreased by 55·3% (49·1–60·5), and then following the launch of Gavi, the Vaccine Alliance when zero-dose counts decreased by another 35·4% (31·5–39·5) from 2000 to 2010. At the super-regional level, the greatest reduction in the number of zero-dose children between 1980 and 2019 was in south Asia, with 19·5 million (95% UI 17·6–21·0) fewer zero-dose children in 2019: an 89·3% (87·9–90·4) decrease. In sub-Saharan Africa, DTP1 coverage nearly doubled between 1980 and 2019, from 42·3% (36·3–48·7) to 78·2% (76·7–79·8). However, the super-regional target population also grew by 125% during that time period, resulting in a more modest reduction of 1·41 million (0·168–2·46) fewer zero-dose children in 2019 than 1980. In 1980, 53·5% (52·3–54·7) of zero-dose children lived in just five countries: India, China, Indonesia, Pakistan, and Bangladesh. By 2019, most (52·8% [51·0–54·3]) zero-dose children still lived in only seven countries: Nigeria, India, Ethiopia, Democratic Republic of the Congo, Brazil, Somalia, and Pakistan. Vaccine coverage trends, 2020–23: effect of the COVID-19 pandemic Global coverage for all original EPI vaccines declined following the onset of the COVID-19 pandemic. Substantial COVID-19 pandemic-related disruptions to global coverage for the original EPI vaccines began in 2020, generally increased in 2021 and 2022, then improved but did not fully resolve by 2023 (Fig. 3 ). The greatest decreases between 2019 (the final pre-pandemic comparator year) and 2023 were estimated for Pol3 coverage (2·8 percentage points [95% UI 0·7–5·0]) and the smallest decreases for DTP1 (1·6 percentage points [0·5–2·9]). Global coverage for most of the newer vaccines continued to expand over the course of the COVID-19 pandemic, driven by both continued introductions and scale-up (Fig. 1 ). The largest gains between 2019 (the year before the COVID-19 pandemic) and 2023 were estimated for PCV3 (14·3 percentage points [95% UI 12·9–15·6]). All newer vaccines reached higher coverage levels in 2023 compared with 2019, except for HepB3. HepB3 is typically given as a part of a pentavalent vaccine with DTP, and global HepB3 coverage more closely mirrored DTP3 coverage and had similar disruptions during this time period. Global HepB3 coverage in 2023 remained 1·6 percentage points (0·2–3·2) lower than that seen in 2019. Compared with a counterfactual scenario absent COVID-related disruptions, global DTP3 coverage was 2·7 percentage points (95% UI 2·4–3·2) lower in 2020, 4·2 percentage points (3·8–4·6) lower in 2021, 2·3 percentage points (2·0–2·9) lower in 2022, and 3·1 percentage points (2·7–3·5) lower in 2023, with similar trends for MCV1, Pol3, and BCG (Fig. 3 ). The COVID-19 pandemic resulted in an estimated 15·6 million (14·4–16·9) fewer children vaccinated with DTP3 globally between 2020 and 2023, 15·6 million (14·4–17·0) fewer with MCV1, 15·9 million (15·0–17·2) with Pol3, and 9·18 million (8·20–10·2) with BCG. Although coverage continued to increase over 2020–23 for newer vaccines, these gains did not keep pace with expectations absent the pandemic (Fig. 3 ). Among the newer vaccines, the largest pandemic impacts were estimated for RotaC, with 16·6 million (15·7–17·7) fewer children vaccinated between 2020 and 2023 than if the pandemic had not occurred, followed by MCV2 (16·5 million [15·3–18·0] fewer children), PCV3 (15·8 million [15·0–16·8]), Hib3 (15·3 million [14·2–16·5]), HepB3 (14·4 million [13·1–15·7]), and RCV1 (13·4 million [12·2–14·7]). Both the magnitude of COVID-19 pandemic-related disruptions to vaccine coverage and the degree of post-pandemic recovery varied by vaccine and super-region. Compared with the COVID-19-free counterfactual scenario, the largest single-year coverage disruptions were all estimated to have occurred in Latin America and the Caribbean, for PCV3 in 2023 and 2021, and DTP1 in 2021 (decreases of 11·6 percentage points [95% UI 9·6–13·9], 11·2 percentage points [9·7–14·1], and 11·2 percentage points [9·6–12·7], respectively). Among other super-regions, greatest single-year disruptions were for RotaC in sub-Saharan Africa in 2022 (a decrease of 7·7 percentage points [7·3–8·7]), RotaC in central Europe, eastern Europe, and central Asia in 2021 (7·2 percentage points [6·7–7·8]), and PCV3 in North Africa and the Middle East in 2021 (7·0 percentage points [6·2–8·4]). As of 2023, coverage of BCG, DTP1, DTP3, MCV1, and Pol3 had recovered to levels near expected without the COVID-19 pandemic (within 1 percentage point) only for BCG in sub-Saharan Africa and central Europe, eastern Europe, and central Asia; DTP1 in south Asia and central Europe, eastern Europe, and central Asia; DTP3 in central Europe, eastern Europe, and central Asia; MCV1 in central Europe, eastern Europe, and central Asia; and Pol3 in south Asia. Sub-Saharan Africa as a super-region saw the greatest cumulative disruptions to vaccine coverage across 2020 to 2023 in absolute numbers for RotaC, PCV3, and Pol3 (6·96 million [95% UI 6·73–7·42], 5·31 million [5·09–5·57], and 4·94 million [4·74–5·19] fewer children vaccinated, respectively). The COVID-19 pandemic also resulted in an estimated 4·12 million (3·90–4·38) additional children missing routine MCV1 vaccination in south Asia and 4·64 million (3·59–5·64) in sub-Saharan Africa. Relative to target population size, cumulative disruptions were greatest in Latin America and the Caribbean, for PCV3, RotaC, and DTP3, with cumulative percent losses in children vaccinated of 9·4% (8·2–10·6), 7·8% (6·7–8·9), and 7·6% (6·5–8·8), respectively. Other notable relative disruptions occurred in north Africa and the Middle East for PCV3 (a cumulative loss of 5·5% [5·1–6·0]), sub-Saharan Africa for RotaC (a cumulative loss of 4·7% [4·5–5·0]), and southeast Asia, east Asia, and Oceania for Pol3 (a cumulative loss of 4·3% [3·9–4·6]). Greatest cumulative absolute and proportional COVID-19 pandemic disruptions tended to occur in Latin America and the Caribbean, sub-Saharan Africa, and south Asia. Trends in zero-dose children, 2020–23: impact of the COVID-19 pandemic and progress needed to reach the IA2030 target of 50% reduction by 2030 The COVID-19 pandemic has reversed previous gains in reducing zero-dose children globally. As of 2023, there were 15·7 million (95% UI 14·6–17·0) zero-dose children worldwide, compared with 14·7 million (13·8–15·6) in 2019: a 2·9% (2·6–3·2) increase. This reversal follows a long period of progress, during which global zero-dose counts decreased from 58·8 million (53·4–64·2) in 1980 to 14·7 million (13·8–15·6) in 2019. The global number of zero-dose children rose to 18·6 million (17·6–20·0) in 2021 before declining, but still remaining above pre-pandemic levels in 2022 and 2023. To reach the IA2030 zero-dose target, the global number of zero-dose children would need to be halved from 2019 levels to 7·35 million (6·92–7·82) by 2030. This would equate to increasing global DTP1 coverage from 87·4% (86·4–88·3) in 2019 to 94·0% (93·6–94·3) in 2023. Between 2020 and 2023, COVID-19 pandemic-related disruptions to DTP1 coverage resulted in a total of 12·8 million (11·7–14·0) additional zero-dose children over these 4 years. South Asia was the only super-region whose DTP1 coverage in 2023 neared levels expected in absence of the pandemic (within 0·8 percentage points [–0·9 to 1·9]). As of 2023, 51·1% (47·7–53·6) of all zero-dose children lived in eight countries, primarily in sub-Saharan Africa and south Asia (Nigeria, India, Democratic Republic of the Congo, Ethiopia, Somalia, Sudan, Indonesia, and Brazil). Compared with 2019, this distribution reflects recent rising numbers of zero-dose children in Sudan and Indonesia and decreases in Pakistan due to rising coverage. Under a scenario in which all countries and territories contribute equally to the IA2030 zero-dose reduction goal, accounting for anticipated population changes, 51·2% (95% UI 35·9–63·9) of the additional zero-dose children (8·34 million [7·12–9·64]) needed to be reached by vaccination in 2030 compared with 2023 would live in eight countries: Nigeria, India, Democratic Republic of the Congo, Sudan, Somalia, Indonesia, Ethiopia, and Viet Nam. The largest absolute reductions in zero-dose children over 2023–30 would be required in sub-Saharan Africa and south Asia (4·28 million [3·46–5·10] and 1·33 million [1·07–1·61], respectively). The super-regions of Latin America and the Caribbean and central Europe, eastern Europe, and central Asia have historically achieved the DTP1 coverage levels that would be needed to reach their IA2030 targets (91·9% [90·7–92·9] and 98·0% [97·5–98·4], respectively). For south Asia, 95·9% (95·5–96·3) of DTP1 coverage would be required by 2030, 2·2 percentage points (1·8–2·5) higher than the highest historical coverage. Sub-Saharan Africa would require 90·3% (89·6–91·0) of DTP1 coverage, 12·1 percentage points (11·4–12·8) higher than highest historical coverage in the super-region. Together, these two super-regions account for 65·1% (62·8–68·6) of the total global reduction in zero-dose children required between 2023 and 2030. At the country level, 18 of 204 countries and territories had reached a 50% reduction in zero-dose children by 2023 (Fig. 4 ). Among those countries and territories with birth cohorts of at least 10 000, Tanzania, Jordan, and Malaysia had the greatest percentage reductions in zero-dose children, whereas Trinidad and Tobago, Ukraine, and Jordan had the greatest percentage point gains in DTP1 coverage. Conversely, compared with 2023 levels, 40 (20%) countries and territories require a more than 10 percentage point increase in DTP1 coverage by 2030, and these account for 62·4% (95% UI 52·4–71·4) of the total reduction in global zero-dose children required over this time. Many countries and territories would need to substantially outpace historical trends to reach 2030 zero-dose targets. Of 186 countries and territories not meeting this target by 2023, only 18 (10%) require a future AROC below the median of historical AROCs, and nearly half (80 [43%]) would need to exceed the 80th percentile of historical AROCs (Fig. 4 C). Among the eight countries needed to contribute the largest reductions in zero-dose children (4·22 million [51·2%] of 8·34 million), seven would need to exceed the 80th percentile of past DTP1 AROCs (Somalia, Sudan, Democratic Republic of the Congo, Viet Nam, Nigeria, Ethiopia, and Indonesia), six would need to exceed the 90th percentile (Somalia, Sudan, Democratic Republic of the Congo, Viet Nam, Nigeria, and Ethiopia), five would need to exceed the 95th percentile (Somalia, Sudan, Democratic Republic of the Congo, Viet Nam, and Nigeria), and two would need to exceed the 99th percentile (Somalia and Sudan). For these countries, improvements in DTP1 coverage would need to outpace almost any gain that any country in the world has achieved since 2000. As of 2019, 38 countries and territories had achieved 99% DTP1 coverage or greater, but this number decreased to 24 countries and territories by 2023. Forecasting progress towards IA2030 90% coverage targets for life-course vaccines To assess progress towards the IA2030 goals of 90% global coverage for life-course vaccines, we forecasted vaccine coverage for three scenarios (reference, better, and worse). By 2030, globally, vaccine coverage under the reference scenario is forecasted to reach 81·3% (95% UI 79·5–82·7) for DTP3 (2·4 percentage points [0·6–3·8] higher than in 2023), 71·1% (69·6–72·5) for PCV3 (8·7 percentage points [7·1–10·1] higher than in 2023), and 76·0% (73·7–78·1) for MCV2 (5·2 percentage points [2·8–7·2] higher than in 2023; Fig. 5 ). In contrast, under the worse scenario, global vaccine coverage could decline between 2023 and 2030 to 68·9% (66·9–70·4) for DTP3, 59·3% (57·4–60·9) for PCV3, and 62·7% (60·1–65·1) for MCV2. Alternatively, under the better scenario, global vaccine coverage could increase to 91·2% (89·4–92·7) for DTP3, 85·7% (84·0–87·3) for PCV3, and 85·3% (83·1–87·1) for MCV2. Even under the better scenario, only DTP3 coverage (historically higher than the more recently introduced MCV2 and PCV3) is forecasted to reach 90% global coverage. However, reference scenario forecasts varied substantially by GBD super-region. 85 of 204 countries and territories are estimated to have reached 90% coverage by 2023 for DTP3, 56 countries for PCV3, and 57 countries for MCV2. Under the reference scenario, an additional 23 countries and territories are forecasted to reach 90% coverage for DTP3 by 2030 (108 of 204 total), 27 countries for PCV3 (83 of 204 total), and 34 countries for MCV2 (91 of 204 total). Notably, only the high-income super-region is expected to reach or retain at least 90% coverage for the three life-course vaccines by 2030 under the reference scenario. Under the better scenario, these achievements would improve to 186 of 204 countries and territories for DTP3, 171 countries for PCV3, and 161 countries for MCV2. Under the worse alternative scenario, all countries and territories that had achieved 90% coverage for DTP3, PCV3, and MCV2 by 2023 would drop below this target by 2030. Discussion Overview of main findings The first five decades of EPI have fundamentally transformed the landscape of global health through the vaccination of more than four billion children, a doubling of coverage for the original EPI vaccines, the successful introduction and scale-up of new life-saving vaccines, and a three-quarters reduction in the number of zero-dose children since 1980. In recent years, however, this progress has stalled and in some areas of the world reversed—a period of stagnation that began in the decade preceding the COVID-19 pandemic for the original EPI vaccines. We estimate that the COVID-19 pandemic resulted in tens of millions of additional children missing doses from across these 11 routine childhood vaccines since 2020, including an additional 12·8 million zero-dose children, compared with expectations had the pandemic not occurred. Although vaccine coverage in 2023 remained lower than expected in the absence of the pandemic, there are signs of recovery across many vaccines and super-regions, thanks to the concerted efforts of local, national, regional, and global vaccine advocates. Five decades on, therefore, the promise of EPI—to extend the life-saving benefits of vaccines to all children around the world—has been only partially fulfilled. As these results underscore, global vaccine coverage targets cannot be met without transformational improvements in equity. Challenges to sustaining and improving on EPI's successes Despite the remarkable public health successes achieved around the globe by routine childhood vaccination over the past 50 years, efforts to preserve and extend these gains face considerable challenges. Inequalities in coverage, including large numbers of children who remain unvaccinated, persist across and within regions, countries and territories, and communities.8, 9, 14, 15, 53, 54 As the present findings highlight—although steep drops in counts of unvaccinated zero-dose children took place over the past five decades in nearly all regions of the world—these successes were not matched in sub-Saharan Africa, where declines were considerably less pronounced. Zero-dose numbers even increased in some areas during certain periods: in sub-Saharan Africa and south Asia during the 1990s, and in Latin America and the Caribbean and in central Europe, eastern Europe, and central Asia after 2010. As of 2023, more than 50% of the world's zero-dose children lived in just eight countries, characterised variously by weak health systems, large birth cohorts, geographical isolation, erosion of vaccine confidence, and exposure to conflict.9 Indeed, our results show that Sudan was close to reaching a 90% DTP1 coverage in 2019, but with civil war arising in 2023 as per Armed Conflict Location and Event Data, coverage nearly halved. Our estimates reflect complex interactions between these interrelated factors and underscore the need for targeted interventions tailored to each circumstance. Effect of the COVID-19 pandemic Starting in 2020, much of the long-term progress achieved in the global campaign to reduce mortality and morbidity through routine immunisation was halted or reversed during the massive global upheaval caused by the COVID-19 pandemic and has not fully recovered since. The crisis and its cascading effects placed extraordinary pressure on health systems and providers, immunisation supply chains, and health spending, which—combined with physical distancing and stay-at-home measures—severely limited the ability of health workers and those in need of care to provide and access services.55 Other studies found during the height of the pandemic that coverage inequalities within regions grew during the pandemic.56 Even after these measures were lifted, the effects of the COVID-19 pandemic had been ongoing. Even as late as 2023, 84% of countries and territories were still reporting some disruption to health services, and immunisation ranked third highest in terms of services disrupted.11, 57 Our estimates show that between 2019 and 2023, global numbers of zero-dose children rose to their highest levels in 2021 at 18·6 million, with counts in 2023 remaining at 15·7 million, 989 000 more than in 2019. In addition, global coverage decreased for all the original EPI vaccines between 2019 and 2023, with the greatest declines occurring in 2021. Our analysis suggests that the COVID-19 pandemic, along with disruptions in immunisation services due to recent conflicts, has resulted in tens of millions of additional children globally missing routine vaccines since 2020, increasing their risk for preventable disease and death. In 2022, 33 countries and territories reported sizeable measles outbreaks, compared with 22 countries and territories in 2021. In addition, increasing numbers of wild-type polio cases were reported in Pakistan and Afghanistan, and new outbreaks of wild-type polio occurred in Malawi and Mozambique in 2024. A resurgence of diphtheria was also reported, with outbreaks in Bangladesh, Nepal, Nigeria, Pakistan, Venezuela, and Yemen.58, 59 These disease trends were already on the rise before the COVID-19 pandemic60 and reflect long-standing inequalities in vaccine coverage but pose a global risk, including to high-income countries and territories where coverage has stagnated or declined in recent years. Despite these challenges, the effect of the COVID-19 pandemic on vaccination coverage could have been even greater. In a previous analysis using partial-year data from the first months of the pandemic, Causey and colleagues estimated 2020 global DTP3 coverage at approximately 76·7%, which is 7·7 percentage points lower than was expected in the absence of the pandemic.18 In contrast, with the benefit of time to account for delayed reporting from many countries and data sources, our present estimates using more complete data indicate that global DTP3 coverage in 2020 was 78·5%, or just 2·7 percentage points lower than expected without the pandemic. The mitigation of the pandemic's influence on vaccine coverage reflects the tremendous efforts of vaccinators worldwide and the concerted and coordinated efforts on the part of immunisation organisations to continue the delivery of essential health services in extremely challenging circumstances.61, 62 Challenges and opportunities in different zero-dose populations Due to the known challenges to vaccine delivery posed by poverty, lack of accessibility, and the presence of civil or regional conflicts,53, 54, 63, 64 research and policy work focused on zero-dose children has concentrated primarily on the urban poor or those living in remote or conflict-affected areas.65, 66, 67 Given the consistently strong relationship between mothers' education and whether their children are immunised,54, 68 there is also growing awareness of the effect of the social construct of gender on vaccination coverage.15 The low societal status of women—manifesting in a lack of resources, agency, and power—is increasingly shown to be one of the most universal factors adversely affecting equitable childhood immunisation.68, 69, 70, 71 Gender inequalities and socioeconomic factors—including migration status, poverty, ethnicity or caste, access to family planning, and geographical setting—intersect to depress childhood immunisation outcomes for under-resourced populations.68, 72 Countries and territories with the highest zero-dose burdens face a demographic double challenge: although the global birth cohort is projected to shrink by 1·6% globally between 2023 and 2030,73 many high-burden countries and territories will have substantial growth in their vaccination target populations. Nigeria, Ethiopia, and Democratic Republic of the Congo—which collectively contain 26·8% (95% UI 24·2–28·8) of global zero-dose children as of 2023—will see birth cohorts expand by 16·1%, 10·6%, and 5·9%, respectively, during this period. These demographic trends translate directly into increased resource requirements for achieving vaccination targets or even maintaining present coverage levels. These population pressures, combined with existing health system constraints, underscore the need for vaccination strategies that scale more rapidly than population growth in these settings, including enhanced outreach services, simplified delivery models, and innovative workforce approaches. Beyond population growth challenges, even successful 50% reductions in zero-dose counts across all countries and territories would still leave 26 countries with less than 90% DTP1 coverage in 2030, reflecting the magnitude of current inequalities in coverage. The diversity of challenges and barriers leading to the failure to immunise varies broadly from country to country and community to community, highlighting the need for new and tailored solutions.65, 66, 67, 74 Strategies such as the Identify-Reach-Monitor-Measure-Advocate framework75 have been proposed as a way to develop and deliver community-specific plans to reach zero-dose children. Some key strategies that have yielded improved vaccine uptake include awareness and education, communication, mobility of vaccination units, community engagement, motivational incentives, positive reinforcement, and assurance of vaccine safety.76, 77 These efforts must be supported by strong evidence and data, including robust, timely, and local estimates of coverage and a better understanding of the location and characteristics of zero-dose children within each country.78 Vaccine hesitancy Although some of the COVID-19 pandemic-specific challenges to vaccination have receded, several key challenges persist—including increasing disparities in resource-constrained, conflict-affected, or politically-volatile countries and territories;79, 80 intensification of migration and displacement; and climate-related crises.10, 11 An additional challenge to progress has been the threat of growing vaccine hesitancy. Deriving from many complex origins, vaccine misinformation81, 82 and scepticism were already challenges before the pandemic, identified by WHO in 2019 as one of the ten leading threats to global health.23, 83, 84 The COVID-19 pandemic, which in many areas bred declining trust in public health institutions85 and polarised opinions about the necessity and safety of vaccination against COVID-19,82 has had varying effects on public perceptions regarding the importance of routine childhood vaccination and willingness to vaccinate. A 2023 global analysis reported that vaccine hesitancy prevalence ranged from a low of 13·3% in the WHO region of the Americas to a high of 27·9% in the Eastern Mediterranean region,86 and even higher in select African countries.87 In the USA, most parents remained convinced of the benefits and effectiveness of childhood vaccines between 2020 and 2022, with confidence levels ranging from 89·5% to 92·5%, although concerns about vaccine safety and side-effects increased over that time,88 and kindergarten vaccine exemption rates in 2023–24 were the highest ever reported.89 Although overall confidence in routine childhood immunisation remains relatively high, the COVID-19 pandemic clearly exposed a vein of public distrust regarding health policy that is likely to influence public perception of childhood vaccines into the future.84 Strategies to improve vaccine confidence include bolstering scientific literacy to protect against an erosion of trust in science, implementing targeted public health campaigns to promote routine childhood immunisation, including community input in scientific research and policy making, engaging with community and religious leaders as advocates for immunisation, and elevating and equipping health-care providers—who remain the most trusted voices on vaccination—to have impactful conversations about decisions to immunise.25, 83, 84 Looking forward to WHO's Immunization Agenda 2030 targets To track progress in vaccination across the life course, IA2030 targets include halving the global number of zero-dose children and achieving 90% global coverage of DTP3, PCV3, MCV2, and HPVc by 2030 (HPVc was not included in the present analysis due to the lack of currently available data). These targets were ambitious at the time of their creation and present even greater challenges now, following the effect of the COVID-19 pandemic on global vaccination rates. For many countries and territories, the IA2030 targets might be achievable, but might require acceleration of progress. In the countries, territories, and super-regions with the largest numbers of non-immunised and under-immunised children, achieving these targets would require extraordinary improvements in vaccination coverage. By 2023, numbers of zero-dose children remained higher than in 2019 in all super-regions except south Asia. Our forecasts indicate that achieving the ambitious IA2030 goal of 90% global coverage by 2030 for each of the life-course vaccines DTP3, PCV3, and MCV228 is also unlikely. Moreover, coverage disparities seen in 2023 for DTP3 and MCV2 will persist in 2030, with coverage rates in sub-Saharan Africa remaining substantially below other super-regions. Our analysis suggests similar challenges in meeting zero-dose reduction goals. Even if optimistic forecast scenarios were to be achieved, or if all countries and territories were to meet zero-dose reduction targets, these results suggest that substantial geographical disparities will persist in 2030—particularly for DTP3 and MCV2. For PCV3, coverage disparities will lessen due to ongoing introductions and scale-up, though would nevertheless persist even in the better scenario. The success of the first 50 years of EPI has only been possible due to broad and sustained cooperation at all levels, from local health workers to national immunisation programmes to regional and global partnerships. At the global level, WHO coordinates and provides vaccination guidance for all countries and territories and plays a central role in data collection. For example, this study relies on 49 710 vaccine-country-years of data reported by country offices that were collected, collated, and reported annually by WHO through the JRF,31 and these estimates additionally benefit from contextual insights regarding these coverage data generated by WUENIC.49 Gavi supports qualifying countries and territories in strengthening their immunisation programmes, and currently provides vaccines for routine immunisation in 54 countries and territories while they work towards more sustained domestic financing strategies.90 This report shows the substantial scaling up of newer vaccines in low-income and middle-income countries and territories, and Gavi has had a central role in supporting these country-led introductions. The US Agency for International Development (USAID) has also had a key role in monitoring vaccine coverage in low-income and middle-income countries through the DHS, which provide a major source of population-based data about vaccination rates at national and local scales. This study includes data from 313 DHS sources, which represent over half (50·2%) of all survey data sources included from low-income and middle-income countries. With recent shifts in the global immunisation funding environment—including the large-scale termination of USAID-supported programmes, announced cuts to US funding for Gavi and WHO, and broader reductions in global commitments to developmental assistance for health—91, 92, 93, 94 the historical and future progress of vaccination programmes is at risk. With reduced fiscal space, any further new vaccine introductions are in jeopardy, vaccination coverage rates might decrease, and the risk of vaccine-preventable disease is heightened. In this time of risk, accurate estimates of vaccine coverage become even more important. With the closure of the DHS programme, strategic and coordinated efforts to assess coverage through targeted surveys and support for country immunisation data systems will be needed. Childhood immunisation is an outstanding investment with excellent returns in health and economic benefits, across countries and territories of all income levels.95, 96, 97, 98 Proposed reductions in immunisation spending are likely to disproportionally affect low-income and middle-income countries, but high-income countries and territories are also likely to incur health-care costs associated with new and more frequent disease outbreaks.99, 100 Europe saw its highest number of measles cases in 2024 since 1997, and the first measles-related death in the last decade in the USA occurred in an unvaccinated child as part of a measles outbreak in Texas in early 2025.101 Without concerted efforts to bolster immunisation rates in all countries and territories, these risks will continue to increase.102 Due to ongoing uncertainty about the final scope and magnitude of proposed funding cuts, the effects of these decisions are not considered in our forecasts of the IA2030 life-course vaccines. However, if these proposed funding cuts are fully implemented, the forecasts presented here, which already show that global coverage is not on track to reach the IA2030 targets, are likely to be too optimistic. Similarly, the scenario of equal contribution presented here with all countries and territories contributing proportionally to 50% zero-dose reduction targets becomes even more unlikely given the disproportionate effects of additional funding constraints. Nevertheless, it is important to note that any gains in coverage and reduction of existing disparities—even if they fall short of the ambitious goals set by IA2030—would still result in massive public health gains. Each percentage point increase in global vaccination coverage represents protection for millions of additional children against deadly diseases. This perspective does not diminish the importance of ambitious targets, but rather emphasises the substantial value of continued, incremental progress in all settings. Limitations Our present estimates of routine childhood vaccination coverage are limited by various methodological considerations. First, although we applied models designed to adjust for bias in vaccine coverage data, we were not able to account for all potential sources of bias. Displaced or otherwise disenfranchised individuals might be under-represented in the data. Survey data might not accurately capture effects such as migration, catch-up vaccination, and differential survival by immunisation status across the age cohorts on which we based our analyses. Both surveys and country-reported data might be limited in their ability to assess immunisation rates in conflict-affected areas, leading to potential overestimation in the absence of data from these locations and time periods. Reporting of surveys and country-reported data was in many instances delayed by the COVID-19 pandemic; while the timing of this study has allowed for catch-up in reporting, decreases in survey participation rates and other forms of reporting biases during that time might have also occurred and are not reflected in this study. Data that relied on parental or observer recall are subject to recall bias, which we did not to adjust for, based on evidence indicating highly variable effects of recall bias on coverage estimates.103, 104, 105 We were also not able to systematically account for methodological variability across surveys. We provide statistical uncertainty from our modelling framework to reflect confidence in the reported coverage values. Although ST-GPR and MR-BRT partially mitigate the limitations of data sparsity in select locations, estimates in such areas might show greater uncertainty. In this analysis, we produce estimates for all national locations included in the GBD 2023 study, including those for which data are sparse and estimates are uncertain. This approach follows the principles of the GBD study,38 which prioritise comprehensive comparisons and recognise that the absence of an estimate often results in the exclusion of that location from strategic planning and policy decisions. Although we aim to select covariates plausibly linked to vaccination coverage, our models do not allow for potential interactions between covariates such as SDI and disruption magnitude or conflict. Due to the multistep nature of ST-GPR, these limitations are most likely to affect data-sparse locations, where estimates are more heavily informed by covariates and regional trends. Similarly, although our modelled estimates of administrative bias allow variation in bias over time where multiple overlapping coverage observations from survey and country-reported data are available, estimates of trends in bias might be less reliable in data-sparse locations, or where abrupt discontinuities in administrative reporting methodology occur (eg, when countries switch to using electronic systems such as DHIS2 for ascertaining vaccine delivery counts). Second, our reliance on DTP1 coverage as a measure of zero-dose children, although standard practice,9, 106 could overestimate the number of those who do not receive any childhood vaccinations, as children might in some cases receive other vaccinations even after missing DTP1. Similarly, our understanding of trends in zero-dose children rely on estimates and forecasts of populations. Following standard GBD practices, we did not account for uncertainty in these population estimates, and the uncertainty intervals for zero-dose and other counts included here thus represent uncertainty only in the associated coverage estimates. The uncertainty intervals for these count-based estimates, therefore, may underestimate the true degree of uncertainty in these measures. Third, our analysis does not include data on vaccinations that take place outside EPI-designated routine childhood immunisation schedules, such as vaccinations administered in limited immunisation campaigns targeting specific populations or administered through private markets (except for selected private vaccinations in China, which are included in our analysis). Due to a lack of comprehensive data, our analysis does not account for catch-up vaccination activities, including global efforts through WHO's Big Catch-Up initiative to reach children who missed routine immunisations during the COVID-19 pandemic.58 Although age-specific survey data can provide some insight into catch-up vaccination, comprehensive administrative data are not available to inform such models. Additional efforts are needed to collect data and develop analytic methods to estimate coverage across all ages, including the effect of catch-up activities. Even so, catch-up activities represent a stop-gap measure that cannot replace improvements to routine health-care services. Our results show that disruptions due to COVID-19 have had long-lasting and persistent effects on routine services, which serve as the foundation for strong immunisation programmes. Fourth, our analysis estimates the size of the effect of the COVID-19 pandemic on vaccine coverage by first estimating coverage in the absence of stockouts or any other disruptions to coverage. We then assume that, absent the COVID-19 pandemic, each country would have had the average degree of coverage disruption due to stockouts or other factors, as was observed from 2015 to 2019. This year range was selected to try to reflect the most recent patterns in disruptions, but nevertheless it is challenging to disentangle the ongoing historical trends from the impacts of the COVID-19 pandemic, and it is not necessarily the case that recent disruption trends would have continued apace. In particular, for countries and territories where large disruptions were common before the COVID-19 pandemic or coverage levels were changing rapidly, we may overestimate or underestimate COVID-19 pandemic-related impacts. Therefore, we have presented the results of this post-hoc analysis in aggregate at super-region and global levels only. In this counterfactual estimation, we do not account for the effect of delays in the introduction of new vaccines that might have occurred due to the COVID-19 pandemic. For these newer vaccines, it is therefore likely that we might underestimate the global effect of the pandemic. Fifth, we imputed disruption estimates for countries and territories without country-reported data during the COVID-19 pandemic, using vaccine-specific and year-specific distributions of disruption magnitudes from locations with available data. As our results show, however, actual disruption magnitudes varied widely. Our results in these country-vaccine-years might thus reflect either overestimation or underestimation of actual disruptions. In particular, many high-income countries and territories have incomplete data reporting during the COVID-19 pandemic and estimates of COVID-19 pandemic-related disruptions in these locations should be interpreted with caution. Sixth, our process for estimating coverage of newer vaccines first as ratios relative to a reference vaccine (DTP3 for HepB3, Hib3, PCV3, and RotaC, and MCV1 for MCV2 and RCV1) constrains our estimates of these newer vaccines to be lower than that of their respective reference vaccines. For vaccines given in combination with the reference vaccine (eg, RCV1 and MCV1, or Hib3 and DTP3), or where these constraints are implied by definition (eg, MCV2 < MCV1, or DTP3 < DTP1), this assumption is appropriate. PCV and rotavirus vaccines, are typically given on the same schedule as DTP; however, coverage could exceed that of DTP3 in rare cases, particularly in the setting of intensive scale-up or vaccine-specific disruptions to DTP3 coverage. Future improvements to this work could consider independent modelling of PCV3 and/or RotaC coverage. Although not a focus of the present analysis, characterising within-country differences in coverage is also important. Assessing coverage by crucial sociodemographic factors—eg, by geography at subnational scales, wealth, education, women's status, refugee status, and race and ethnicity—can help identify persistent disparities in routine childhood vaccination masked by the national overview estimates presented here. Similarly, although HPVc is one of IA2030's 90% life-course vaccine coverage targets and has been recommended globally by WHO since 2009,107 we were not able to generate estimates or forecasts of HPVc coverage due to the lack of currently available survey data in most settings. Additional work will be needed to generate coverage estimates for HPVc and other vaccines not included here, using rigorous statistical frameworks that can leverage both survey and administrative data sources. In this report, we did not measure rates of under-vaccinated children, those who have received only some but not all vaccine doses in their vaccination schedule, or assess patterns in the timeliness of vaccination. Comprehensive estimates of the full spectrum of vaccination, beyond the coverage metrics presented here, would improve understanding of population susceptibility and risks of disease outbreaks. Conclusions Over the past 50 years, EPI has achieved extraordinary success in the urgent public health campaign to immunise the world's children against life-threatening diseases. The next 50 years will require sustained efforts at global, regional, national, and community levels to successfully preserve and extend existing gains. Enduring coverage inequities and the persistent effects of the COVID-19 pandemic only serve to underscore the importance of advancing routine childhood vaccination, one of the most powerful public health interventions known. Current trends and forecasts, along with proposed reductions to global immunisation financing, suggest that reaching the ambitious goals of IA2030—aimed at reducing mortality and morbidity from vaccine-preventable diseases for everyone, everywhere—is unlikely to be realised unless the global community redoubles its commitment to equitable and universal vaccination strategies. Effective programmes and policies must integrate vaccination services into revitalised primary health-care systems, focus on context-specific and community-driven immunisation strategies, increase and optimise investment in vaccination, and prioritise community-led approaches to build vaccine confidence. Yet these present and future challenges should be met with firm confidence in the power and promise of vaccination, rooted in the successes of the past 50 years of EPI. It is important that the global health community embrace our shared responsibility and whole-heartedly reaffirm our collective commitment to routine childhood vaccination to deliver on the promise of EPI to provide all people, everywhere the opportunity to live full and healthy lives. Declarations Contributors Shaunt Papelian Declarations of interests The author has no conflict of interest Funding No funding was received for conducting this study Data sharing This study follows the Guidelines for Accurate and Transparent Health Estimates Reporting (GATHER). To download the estimates produced in these analyses, please visit the Global Health Data Exchange website at https://ghdx.healthdata.org/record/ihme-data/gbd-2023-vaccinationcoverage-1980-2030. References WHO. WorldHealthAssembly. WHO. Essentialprogrammeonimmunization. https://www.who.int/teams/immunization-vaccines-and-biologicals/essentialprogramme-on-immunization (accessedJuly30,2024). Shattock AJ, Johnson HC, Sim SY. Contribution of vaccination to improved survival and health: modelling 50 years of the Expanded Programme on Immunization. Lancet. 2024;403:2307–16. Institute for Health Metrics and Evaluation. Financing global health 2023: the future of health financing in the post-pandemic era. Institute for Health Metrics and Evaluation; 2024. Sim SY, Watts E, Constenla D, Brenzel L, Patenaude BN. Return on investment from immunization against 10 pathogens in 94 low- and middle-income countries, 2011–30. Health Aff (Millwood). 2020;39:1343–53. Johns Hopkins University, International Vaccine Access Center. Methodology report: Decade of Vaccines Economics (DOVE) return on investment analysis. International Vaccine Access Center; 2019. Ozawa S, Clark S, Portnoy A, Grewal S, Brenzel L, Walker DG. Return on investment from childhood immunization in low- and middleincome countries, 2011–20. Health Aff (Millwood). 2016;35:199–207. GBD2020,Release1,VaccineCoverageCollaborators.Measuringroutinechildhoodvaccinationcoveragein204countriesandterritories,1980–2019:asystematicanalysisfortheGlobalBurdenofDiseaseStudy2020,release1.Lancet2021;398:503–21. WHO. Progress and challenges with achieving universal immunization coverage: 2023 WHO/UNICEF Estimates of National Immunization Coverage (WUENIC). World Health Organization; 2024. WHO. Immunization agenda 2030: a global strategy to leave no one behind. World Health Organization; 2020. IA2030 Coordination Group. IA2030technicalprogressreport2023.ImmunizationAgenda2030,2023. Colomé-Hidalgo M, Donado Campos J, Gil de Miguel Á. Monitoring inequality changes in full immunization coverage in infants in Latin America and the Caribbean. Rev Panam Salud Publica. 2020;44:e56. Guzman-Holst A, DeAntonio R, Prado-Cohrs D, Juliao P. Barriers to vaccination in Latin America: a systematic literature review. Vaccine. 2020;38:470–81. Local Burden of Disease Vaccine Coverage Collaborators. Mapping routine measles vaccination in low- and middle-income countries. Nature. 2021;589:415–19. Chopra M, Bhutta Z, Chang Blanc D. Addressing the persistent inequities in immunization coverage. Bull World Health Organ. 2020;98:146–48. Islam MR, Rahman MM, Rahman MS, Abe SK, Akmatov MK, Hashizume M. Trends and projections of age-appropriate vaccination coverage in 41 low- and middle- income countries in Asia and subSaharan Africa, 2000–2030. Front Public Health. 2024;12:1371258. Wendt A, Santos TM, Cata-Preta BO. Exposure of zero-dose children to multiple deprivation: analyses of data from 80 low- and middle-income countries. Vaccines (Basel). 2022;10:1568. Causey K, Fullman N, Sorensen RJD. Estimating global and regional disruptions to routine childhood vaccine coverage during the COVID-19 pandemic in 2020: a modelling study. Lancet. 2021;398:522–34. Lassi ZS, Naseem R, Salam RA, Siddiqui F, Das JK. The impact of the COVID-19 pandemic on immunization campaigns and programs: a systematic review. Int J Environ Res Public Health. 2021;18:988. UNICEF.Morethan117 millionchildrenatriskofmissingoutonmeaslesvaccines,asCOVID-19surges.April13. 2020. https://www.unicef.org/press-releases/more-117-million-children-risk-missingout-measles-vaccines-covid-19-surges(accessedJuly30,2024 ). WHO.COVID-19pandemicfuelslargestcontinuedbackslideinvaccinationsinthreedecades.July15. 2022. https://www.who.int/news/item/15-07-2022-covid-19-pandemic-fuels-largest-continuedbackslide-in-vaccinations-in-three-decades(accessedJuly30,2024 ). Wagenaar BH, Augusto O, Beste J. The 2014–2015 Ebola virus disease outbreak and primary healthcare delivery in Liberia: timeseries analyses for 2010–2016. PLoS Med. 2018;15:e1002508. Eagan RL, Larson HJ, de Figueiredo A. Recent trends in vaccine coverage and confidence: a cause for concern. Hum Vaccin Immunother. 2023;19:2237374. UNICEF. The state of the world’s children 2023: for every child, vaccination. UNICEF Innocenti, Global Office of Research and Foresight; 2023. WHO. The Global Vaccine Action Plan 2011–2020. Review and lessons learned. World Health Organization; 2019. WHO. Implementing the Immunization Agenda 2030: a framework for action through coordinated planning, monitoring & evaluation, ownership & accountability, and communications & advocacy. World Health Organization; 2021. UN. Ensure healthy lives and promote well-being for all at all ages. https://sdgs.un.org/goals/goal3#targets_and_indicators (accessed April 10, 2025). IA2030 Scorecard. Immunization Agenda 2030 scorecard: overview dashboard. https://scorecard.immunizationagenda2030.org (accessed Nov 19, 2024). Cata-Preta BO, Santos TM, Mengistu T, Hogan DR, Barros AJD, Victora CG. Zero-dose children and the immunisation cascade: understanding immunisation pathways in low and middle-income countries. Vaccine. 2021;39:4564–70. WHO. WHO/UNICEF estimates of national immunization coverage. https://www.who.int/teams/immunization-vaccines-and-biologicals/immunization-analysis-and-insights/global-monitoring/immunization-coverage/who-unicef-estimates-of-national-immunization-coverage (accessed July 30, 2024). WHO. WHO/UNICEF joint reporting process. https://www.who.int/teams/immunization-vaccines-and-biologicals/immunization-analysis-and-insights/global-monitoring/who-unicef-joint-reporting-process (accessed July 30, 2024). Burton A, Monasch R, Lautenbach B, et al. WHO and UNICEF estimates of national infant immunization coverage: methods and processes. Bull World Health Organ. 2009;87:535–41. Pond B, Bekele A, Mounier-Jack S, Teklie H, Getachew T. Estimation of Ethiopia's immunization coverage—20years of discrepancies. BMC Health Serv Res. 2021;21(suppl 1):587. Mboussou F, Kada S, Danovaro-Holliday MC, et al. Status of routine immunization coverage in the World Health Organization african region three years into the COVID-19 pandemic. Vaccines (Basel). 2024;12:168. Rau C, Lüdecke D, Dumolard LB, et al. Data quality of reported child immunization coverage in 194 countries between 2000 and 2019. PLOS Glob Public Health. 2022;2:e0000140. Institute for Health Metrics and Evaluation. Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) protocol. June 4. 2024. https://www.healthdata.org/sites/default/files/2024-06/GBD%20Protocol%20060424.pdf (accessed July 30, 2024). GBD 2021 Diseases and Injuries Collaborators. Global incidence, prevalence, years lived with disability (YLDs), disability-adjusted life-years (DALYs), and healthy life expectancy (HALE) for 371 diseases and injuries in 204 countries and territories and 811 subnational locations, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021. Lancet. 2024;403:2133–61. Zheng P, Barber R, Sorensen RJD, Murray CJL, Aravkin AY. Trimmed constrained mixed effects models: formulations and algorithms. J Comput Graph Stat. 2021;30:544–56. Stevens GA, Alkema L, Black RE, et al. Guidelines for accurate and transparent health estimates reporting: the GATHER statement. Lancet. 2016;388:e19–23. IHME. Global Burden of Disease Study 2023. (GBD 2023) routine childhood vaccination coverage estimates and forecasts 1980–2030. May 15, 2025. https://ghdx.healthdata.org/record/ihme-data/gbd-2023-vaccination-coverage-1980-2030 (accessed June 2, 2025). WHO. Immunization data: vaccination schedule. https://immunizationdata.who.int/global?topic=Vaccinationschedule&location= (accessed Aug 9, 2024). WHO. Immunization data: vaccine supply and logistics. https://immunizationdata.who.int/global/wiise-detail-page/vaccine-supply-and-logistics (accessed Jan 30, 2025). WHO. Immunization data: vaccine introduction. https://immunizationdata.who.int/global?topic=Vaccineintroduction&location= (accessed Aug 9, 2024). WHO. Immunization data. https://immunizationdata.who.int/global (accessed Jan 30, 2025). Bloland P, MacNeil A. Defining & assessing the quality, usability, and utilization of immunization data. BMC Public Health. 2019;19:380. GBD 2019 Healthcare Access and Quality Collaborators. Assessing performance of the Healthcare Access and Quality Index, overall and by select age groups, for 204 countries and territories, 1990–2019: a systematic analysis from the Global Burden of Disease Study 2019. Lancet Glob Health. 2022;10:e1715–43. Murray CJ, Ezzati M, Flaxman AD, et al. GBD 2010: design, definitions, and metrics. Lancet. 2012;380:2063–66. GBD 2021 Demographics Collaborators. Global age-sex-specific mortality, life expectancy, and population estimates in 204 countries and territories and 811 subnational locations, 1950–2021, and the impact of the COVID-19 pandemic: a comprehensive demographic analysis for the Global Burden of Disease Study 2021. Lancet. 2024;403:1989–2056. WHO, UNICEF. WUENIC trends. https://worldhealthorg.shinyapps.io/wuenic-trends/ (accessed April 4, 2025). Vollset SE, Goren E, Yuan C-W, et al. Fertility, mortality, migration, and population scenarios for 195 countries and territories from 2017 to 2100: a forecasting analysis for the Global Burden of Disease Study. Lancet. 2020;396:1285–306. Foreman KJ, Marquez N, Dolgert A, et al. Forecasting life expectancy, years of life lost, and all-cause and cause-specific mortality for 250 causes of death: reference and alternative scenarios for 2016-40 for 195 countries and territories. Lancet. 2018;392:2052–90. GBD 2021 Forecasting Collaborators. Burden of disease scenarios for 204 countries and territories, 2022–2050: a forecasting analysis for the Global Burden of Disease Study 2021. Lancet. 2024;403:2204–56. WHO. Explorations of inequality: childhood immunization. World Health Organization; 2018. Ali HA, Hartner A-M, Echeverria-Londono S, et al. Vaccine equity in low and middle income countries: a systematic review and meta-analysis. Int J Equity Health. 2022;21:82. Shet A, Carr K, Danovaro-Holliday MC, et al. Impact of the SARS-CoV-2 pandemic on routine immunisation services: evidence of disruption and recovery from 170 countries and territories. Lancet Glob Health. 2022;10:e186–94. Lai X, Zhang H, Pouwels KB, Patenaude B, Jit M, Fang H. Estimating global and regional between-country inequality in routine childhood vaccine coverage in 195 countries and territories from 2019 to 2021: a longitudinal study. EClinicalMedicine. 2023;60:102042. WHO. Fourth round of the global pulse survey on continuity of essential health services during the COVID-19 pandemic: November 2022–January 2023. World Health Organization; 2023. WHO, UNICEF. Gavi, the Vaccine Alliance. The Big Catch-up: an essential immunization recovery plan for 2023 and beyond. World Health Organization; 2023. Lubanga AF, Bwanali AN, Kangoma M, et al. Addressing the re-emergence and resurgence of vaccine-preventable diseases in Africa: a health equity perspective. Hum Vaccin Immunother. 2024;20:2375081. WHO. Measles: global situation. Nov 27. 2019. https://www.who.int/emergencies/disease-outbreak-news/item/2019-DON211 (accessed April 10, 2025). WHO. Immunization as an essential health service: guiding principles for immunization activities during the COVID-19 pandemic and other times of severe disruption. World Health Organization; 2020. Dixit SM, Sarr M, Gueye DM, et al. Addressing disruptions in childhood routine immunisation services during the COVID-19 pandemic: perspectives from Nepal, Senegal and Liberia. BMJ Glob Health. 2021;6:e005031. Grundy J, Biggs B-A. The impact of conflict on immunisation coverage in 16 countries. Int J Health Policy Manag. 2019;8:211–21. Bangura JB, Xiao S, Qiu D, Ouyang F, Chen L. Barriers to childhood immunization in sub-Saharan Africa: a systematic review. BMC Public Health. 2020;20:1108. Nandy R, Rees H, Bernson J, Digre P, Rowley E, McIlvaine B. Tackling inequities in immunization outcomes in urban contexts. Jan 12, 2018. https://global.comminit.com/content/tackling-inequities-immunization-outcomes-urban-contexts (accessed Oct 29, 2024). Okwo-Bele J-M, Conner R, McIlvaine B, Rowley E, Bernson J. Tackling inequities in immunization outcomes in conflict contexts. Jan 12, 2018. https://www.comminit.com/global/content/tackling-inequities-immunization-outcomes-conflict-contexts (accessed Oct 29, 2024). Levine O, Lemango ET, Bernson J, Gurley N, Rowley E, McIlvaine B. Tackling inequities in immunization outcomes in remote rural contexts. Jan 12, 2018. https://global.comminit.com/content/tackling-inequities-immunization-outcomes-remote-rural-contexts (accessed Oct 29, 2024). Feletto M, Sharkey A, Rowley E et al. A gender lens to advance equity in immunization. July 5, 2019. https://global.comminit.com/content/gender-lens-advance-equity-immunization (accessed Oct 31, 2024). Kalbarczyk A, Brownlee N, Katz E. Of money and men: a scoping review to map gender barriers to immunization coverage in low- and middle-income countries. Vaccines (Basel). 2024;12:625. Feletto M, Sharkey A. The influence of gender on immunisation: using an ecological framework to examine intersecting inequities and pathways to change. BMJ Glob Health. 2019;4:e001711. Merten S, Martin Hilber A, Biaggi C, et al. Gender determinants of vaccination status in children: evidence from a meta-ethnographic systematic review. PLoS ONE. 2015;10:e0135222. Equity Reference Group for Immunization. Tackling inequities in immunisation outcomes: a gender lens. January, 2019. https://drive.google.com/file/d/1KowBaWNtYAsW42MJBjRVSDoe_QCbmB4-/view?usp=embed_facebook (accessed Oct 31, 2024). GBD 2021 Fertility and Forecasting Collaborators. Global fertility in 204 countries and territories, 1950–2021, with forecasts to 2100: a comprehensive demographic analysis for the Global Burden of Disease Study 2021. Lancet. 2024;403:2057–99. Equity Reference Group for Immunization. ERG advocacy brief. 2019. https://drive.google.com/file/d/1VpuVX85RWd_vq6FJ4lcmCnPOYJp1AhuM/view?usp=sharing&usp=embed_facebook (accessed Oct 26, 2024). Gavi, the Vaccine Alliance. Guidance on use of Gavi support to reach zero dose children and missed communities. Gavi, 2021. Tuckerman J, Kaufman J, Danchin M. Effective approaches to combat vaccine hesitancy. Pediatr Infect Dis J. 2022;41:e243–45. de Koning R, Gonzalez Utrilla M, Spanaus E, Moore M, Lomazzi M. Strategies used to improve vaccine uptake among healthcare providers: a systematic review. Vaccine X. 2024;19:100519. Hogan D, Gupta A. Why reaching zero-dose children holds the key to achieving the Sustainable Development Goals. Vaccines (Basel). 2023;11:781. World Bank Group. World Bank Group strategy for fragility, conflict, and violence 2020–2025. Feb 26. 2020. https://www.worldbank.org/en/topic/fragilityconflictviolence/publication/world-bank-group-strategy-for-fragility-conflict-and-violence-2020-2025 (accessed Nov 22, 2024). World Bank Group. Classification of fragile and conflict-affected situations. June 28. 2024. https://www.worldbank.org/en/topic/fragilityconflictviolence/brief/classification-of-fragile-and-conflict-affected-situations (accessed Nov 22, 2024). Kata A. A postmodern Pandora's box: anti-vaccination misinformation on the internet. Vaccine. 2010;28:1709–16. de Figueiredo A, Temfack E, Tajudeen R, Larson HJ. Declining trends in vaccine confidence across sub-Saharan Africa: a large-scale cross-sectional modeling study. Hum Vaccin Immunother. 2023;19:2213117. WHO. Ten threats to global health in 2019. https://www.who.int/news-room/spotlight/ten-threats-to-global-health-in-2019 (accessed Nov 4, 2024). Opel DJ, Brewer NT, Buttenheim AM, et al. The legacy of the COVID-19 pandemic for childhood vaccination in the USA. Lancet. 2023;401:75–8. Robert Wood Johnson Foundation. The public's perspective on the United States public health system. May 1. 2021. https://www.rwjf.org/content/rwjf-web/us/en/insights/our-research/2021/05/the-publics-perspective-on-the-united-states-public-health-system.html (accessed Nov 13, 2024). Abenova M, Shaltynov A, Jamedinova U, Semenova Y. Worldwide child routine vaccination hesitancy rate among parents of children aged 0–6 years: a systematic review and meta-analysis of cross-sectional studies. Vaccines (Basel). 2023;12:31. Anjorin AA, Odetokun IA, Abioye AI, et al. Will Africans take COVID-19 vaccination? PLoS ONE. 2021;16:e0260575. Shah MD, Szilagyi PG, Shetgiri R, et al. Trends in parents' confidence in childhood vaccines during the COVID-19 pandemic. Pediatrics. 2022;150:e2022057855. Seither R, Yusuf OB, Dramann D, et al. Coverage with selected vaccines and exemption rates among children in kindergarten—United States, 2023–24 school year. MMWR Morb Mortal Wkly Rep. 2024;73:925–32. Gavi, the Vaccine Alliance. April,. Vaccine funding guidelines. 2023. https://www.gavi.org/sites/default/files/programmes-impact/Vaccine_FundingGuidelines.pdf (accessed April 4, 2025). The White House. Reevaluating and realigning United States Foreign Aid. Jan 20. 2025. https://www.whitehouse.gov/presidential-actions/2025/01/reevaluating-and-realigning-united-states-foreign-aid/ (accessed April 4, 2025). The White House. Withdrawing the United States from the World Health Organization. Jan 20. 2025. https://www.whitehouse.gov/presidential-actions/2025/01/withdrawing-the-united-states-from-the-worldhealth-organization/ (accessed April 4, 2025). Government of the Netherlands. Foreign trade and development minister Reinette Klever: Dutch interests at the heart of development policy. Feb 20. 2025. https://www.government.nl/latest/news/2025/02/20/minister-reinette-klever-dutch-interests-at-the-heart-of-development-policy (accessed April 4, 2025). Walker P. Dismay as UK poised to cut funding for global vaccination group Gavi. Feb 10, 2025. https://www.theguardian.com/society/2025/feb/10/dismay-as-uk-poised-to-cut-funding-for-global-vaccination-group-gavi (accessed April 4, 2025). Zhou F, Jatlaoui TC, Leidner AJ, et al. Health and economic benefits of routine childhood immunizations in the era of the vaccines for children program—United States, 1994–2023. MMWR Morb Mortal Wkly Rep. 2024;73:682–85. Ozawa S, Clark S, Portnoy A, Grewal S, Brenzel L, Walker DG. Return on investment from childhood immunization in low- and middle-income countries, 2011–20. Health Aff (Millwood). 2016;35:199–207. Sim SY, Watts E, Constenla D, Brenzel L, Patenaude BN. Return on investment from immunization against 10 pathogens in 94 low- and middle-income countries, 2011–30. Health Aff (Millwood). 2020;39:1343–53. Lindstrand A, Cherian T, Chang-Blanc D, Feikin D, O'Brien KL. The world of immunization: achievements, challenges, and strategic vision for the next decade. J Infect Dis. 2021;224(suppl 2):S452–67. WHO. European Region reports highest number of measles cases in more than 25 years—UNICEF, WHO/Europe. March 13. 2025. https://www.who.int/europe/news/item/13-03-2025-european-region-reports-highest-number-of-measles-cases-in-more-than-25-years---unicef--who-europe (accessed April 4, 2025). Nandi A, Shet A. Why vaccines matter: understanding the broader health, economic, and child development benefits of routine vaccination. Hum Vaccin Immunother. 2020;16:1900–04. WHO. Measles—United States of America. March 27. 2025. https://www.who.int/emergencies/disease-outbreak-news/item/2025-DON561 (accessed April 4, 2025). WHO. The impact of suspensions and reductions in health official development assistance on health systems. World Health Organization; 2025. Dansereau E, Brown D, Stashko L, Danovaro-Holliday MC. A systematic review of the agreement of recall, home-based records, facility records, BCG scar, and serology for ascertaining vaccination status in low and middle-income countries. Gates Open Res. 2020;3:923. Miles M, Ryman TK, Dietz V, Zell E, Luman ET. Validity of vaccination cards and parental recall to estimate vaccination coverage: a systematic review of the literature. Vaccine. 2013;31:1560–68. Murray CJL, Shengelia B, Gupta N, Moussavi S, Tandon A, Thieren M. Validity of reported vaccination coverage in 45 countries. Lancet. 2003;362:1022–27. Jones CE, Danovaro-Holliday MC, Mwinnyaa G, et al. Routine vaccination coverage—worldwide, 2023. MMWR Morb Mortal Wkly Rep. 2024;73:978–84. WHO. WHO position paper on human papillomavirus (HPV) vaccines. World Health Organization; 2009. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7340665","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Systematic Review","associatedPublications":[],"authors":[{"id":498658449,"identity":"f71365ca-f666-4994-b3ac-9901be7f45e6","order_by":0,"name":"Shaunt Papelian","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAw0lEQVRIiWNgGAWjYNACAwk5fgiLmVgtFTbGkg2kaTmTlrjhALFa5Gc3P3vwse0w4+Ybyc8+MFRYJzYQ0mJw55i54cy2w8xmN9KMZzCcSSdCi0SCmTRv22E2sxs5zAyMbYcJa5Gfkf5N+m/bYR7jGSAt/4jQwnAjx0wa6H0JAwmQlgYitBjcOVNu2FNhYyBx5pkxQ8KxdGPCDpvdvu3BDwOJ+v725McMH2qsZQk7TIKBDcFJIKgcQ8soGAWjYBSMAmwAABRvPh9s7SifAAAAAElFTkSuQmCC","orcid":"","institution":"University of California","correspondingAuthor":true,"prefix":"","firstName":"Shaunt","middleName":"","lastName":"Papelian","suffix":""}],"badges":[],"createdAt":"2025-08-10 19:38:15","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7340665/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7340665/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":88893574,"identity":"c1db2e0a-e6ab-4d08-9dc2-9da8870f8ef6","added_by":"auto","created_at":"2025-08-12 12:57:05","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":175801,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eGlobal and super-regional estimates of vaccine coverage over time\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eMean global (A) and super-regional (B) coverage estimates for the target age population by year for each vaccine, with 95% uncertainty intervals. The dashed horizontal line indicates the coverage required to meet the IA2030 goal of 90% coverage for life-course vaccines. DTP1=diphtheria-tetanus-pertussis, first dose. DTP3=diphtheria-tetanus-pertussis, third dose. Gavi=Gavi, the Vaccine Alliance. HepB3=hepatitis B vaccine, third dose. Hib3=Haemophilus influenzae type b vaccine, third dose. IA2030=Immunization Agenda 2030. MCV1=measles-containing vaccine, first dose. MCV2=measles-containing vaccine, second dose. PCV3=pneumococcal conjugate vaccine, third dose. Pol3=polio vaccine, third dose. RCV1=rubella-containing vaccine, first dose. RotaC=completed rotavirus series.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-7340665/v1/9c4b36c06980720f4ee5676c.png"},{"id":88893570,"identity":"f8b518bc-edf0-446f-a737-93bb464483dd","added_by":"auto","created_at":"2025-08-12 12:57:05","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":176169,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eGlobal and super-regional trends in zero-dose children over time\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e(A) Global and super-regional mean DTP1 coverage estimates for the population younger than 1 year with 95% uncertainty intervals by year for 1980–2023. (B) Super-regional and global (full bars) estimates of zero-dose children by year for 1980–2023. (C) DTP1 coverage estimates and zero-dose children estimates separated by super-region. For all plots, the dashed horizontal lines and corresponding points or bars shown in 2030 represent values that would be required to meet the IA2030 50% zero-dose reduction goal. DTP1=diphtheria-tetanus-pertussis, first dose. IA2030=Immunisation Agenda 2030. EPI=Expanded Programme on Immunisation. Gavi=Gavi, the Vaccine Alliance.\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-7340665/v1/6d2b64f9ea2efa6ae3a018d4.png"},{"id":88895915,"identity":"70f50b16-bd5a-4c57-8781-22010e693633","added_by":"auto","created_at":"2025-08-12 13:05:05","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":78220,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eEffects of the COVID-19 pandemic on global vaccine coverage\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eComparisons of global vaccine coverage estimates for the target population during the COVID-19 pandemic (blue line) versus those expected in the absence of COVID-19 pandemic-associated disruptions (orange line), with 95% uncertainty intervals. COVID-19 pandemic-related disruptions were estimated for 2020–23; coverage estimates for 2015–19 are included as a reference. DTP1=diphtheria-tetanus-pertussis, first dose. DTP3=diphtheria-tetanus-pertussis, third dose. HepB3=hepatitis B vaccine, third dose. Hib3=\u003cem\u003eHaemophilus influenzae\u003c/em\u003e type b vaccine, third dose. MCV1=measles-containing vaccine, first dose. MCV2=measles-containing vaccine, second dose.\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-7340665/v1/0a264b969587f8bbbb468558.png"},{"id":88893575,"identity":"bc0f43aa-d90d-4e5c-9dbe-fe38dd4d9e23","added_by":"auto","created_at":"2025-08-12 12:57:05","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":152588,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eChange required to reach the IA2030 goal of 50% reduction in zero-dose children\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e(A) Map of percentage point change from DTP1 coverage for children younger than 1 year in 2023 required by each country to reach the IA2030 goal of a 50% reduction in zero-dose children by 2030. (B) The AROC in DTP1 coverage from 2023 required to reach the 50% reduction in zero-dose children by 2030. (C) The AROC in DTP1 coverage required between 2023 and 2030 to achieve the same goal, expressed as a percentile of the distribution of all country-level DTP1 coverage AROCs from all 7-year periods between 2000 and 2019. DTP1=diphtheria-tetanus-pertussis, first dose. AROC=annualised rate of change. IA2030=Immunization Agenda 2030.\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-7340665/v1/7666540639fbd5e04883c787.png"},{"id":88895916,"identity":"88951cf3-3b03-419a-8329-bc647c5822bf","added_by":"auto","created_at":"2025-08-12 13:05:05","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":60306,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eForecasted global vaccine coverage\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eHistorical mean global vaccine coverage for 1980–2023 and forecast coverage for the target population for 2024–30 for DTP3, MCV2, and PCV3. Forecasts are displayed for the reference scenario along with better and worse scenarios, as well as 95% uncertainty intervals for all scenarios. Better and worse scenarios are calculated with the 85th and 15th percentiles of past rates of change in coverage, respectively. For all plots, the dashed horizontal line indicates the coverage required to meet the IA2030 goal of 90% coverage for life-course vaccines. DTP3=diphtheria-tetanus-pertussis, third dose. MCV2=measles-containing vaccine, second dose. PCV3=pneumococcal conjugate vaccine, third dose. IA2030=Immunization Agenda 2030.\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-7340665/v1/4e773f7707efb5f29c0050ca.png"},{"id":89064044,"identity":"121cfa98-d978-40ce-89f5-336f6b1c3ed7","added_by":"auto","created_at":"2025-08-14 10:17:25","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1321883,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7340665/v1/4faef9d7-1ef4-4f18-816e-bb4197034806.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Global and national trends in childhood vaccination coverage from 1980 to 2023 with forecasts to 2030","fulltext":[{"header":"Introduction","content":"\u003cp\u003eBuilding on the success of the global campaign to eradicate smallpox, the Expanded Programme on Immunisation (EPI) was launched in 1974 by WHO to extend the benefits of universal immunisation against common childhood diseases worldwide.1 EPI initially supported the deployment of vaccines to combat diphtheria, tetanus, pertussis, polio, measles, and tuberculosis. Over the ensuing 50 years, EPI\u0026mdash;now renamed the Essential Programme on Immunization\u0026mdash;has added more childhood vaccinations, recommending vaccinations for all children globally against hepatitis B, \u003cem\u003eHaemophilus influenzae\u003c/em\u003e type b, pneumococcus, rotavirus, and rubella, along with a second dose of the measles vaccine, while broadening to include recommendations for adolescent vaccination against human papillomavirus.2 Through partnerships between local health-care workers, national immunisation programmes, regional authorities, and international organisations, EPI has achieved remarkable health gains. The effect of making routine childhood immunisation (ie, regular and ongoing immunisation services, often delivered during routine health visits) widely available has been drastic, resulting in an estimated 154\u0026nbsp;million deaths averted globally between 1974 and 2024, with nearly 95% of those in children younger than 5 years.3\u003c/p\u003e\u003cp\u003eAlthough delivering routine childhood vaccinations worldwide requires a tremendous investment of global resources, including approximately US\u003cspan\u003e$\u003c/span\u003e3\u0026middot;9\u0026nbsp;billion in development assistance for health in 2023,4 childhood immunisation has proven to be one of the most successful and cost-effective public health strategies known, both in terms of lives saved and return on investment.5, 6 Estimates have shown the financial rate of return to be in some instances up to 44-times the cost of vaccination.7 Yet the remarkable successes of EPI have slowed in the past decade and in some cases reversed, suggesting weaknesses in health services that were further exposed during the global upheaval caused by the COVID-19 pandemic, including social distancing measures, health system diversions, and supply chain disruptions. Previous estimates suggest that coverage with the third dose of the diphtheria, tetanus, and pertussis vaccine (DTP3) decreased in 94 countries and territories between 2010 and 2019, and only 11 countries worldwide were estimated to have reached the 2019 target set by the WHO Global Vaccine Action Plan of at least 90% coverage for all assessed vaccines.8 As coverage has stalled, new and increased outbreaks of vaccine-preventable illness, such as measles, polio, and diphtheria, have emerged in many countries and territories.9\u003c/p\u003e\u003cp\u003eTo successfully further the reach, equity, and sustainability of global immunisation systems, it is necessary to overcome enduring and emerging challenges, such as growing economic uncertainty and geopolitical instability that constrain funding for vaccination and global health, migration, and population displacement,10, 11 geographical and sociodemographic disparities in access to vaccines,12, 13, 14, 15, 16, 17 disruptions to immunisation delivery related to events such as natural disasters or widespread infectious disease outbreaks such as those caused by the SARS-CoV-2 and Ebola viruses,18, 19, 20, 21, 22 and an upsurge in vaccine misinformation and hesitancy as detailed by the Vaccine Confidence Project.23, 24 To meet these challenges, WHO's World Health Assembly endorsed Immunization Agenda 2030 (IA2030),10 an updated framework to envision and achieve universal immunisation, building on the previous Global Vaccine Action Plan approach with a broader scope and increased tailoring for local contexts.25 Focused on centring the expertise of local and country-level partners and authorities,26 aligned with the UN's Sustainable Development Goal 3 to ensure healthy lives and promote wellbeing for all at all ages,27 IA2030 sets an ambitious global agenda to achieve \u0026ldquo;a world where everyone, everywhere, at every age, fully benefits from vaccines to improve health and well-being\u0026rdquo;.28 One of IA2030's primary goals is to promote equity by halving (relative to 2019) the number of zero-dose children, that is, children missed by routine childhood vaccination, typically proxied by estimating those who have not received any DTP doses. Zero-dose children are more likely to miss out on subsequent vaccinations29 and experience other types of deprivation,17 and strategies to reach these missed children with vaccination services can bolster routine health services more broadly. IA2030 further emphasises the necessity of extending the benefits of vaccination throughout the life course, reaching beyond early childhood to deliver essential catch-up vaccinations and booster doses, along with a growing number of new vaccines scheduled for administration after childhood. To this end, IA2030 sets a goal of achieving 90% global coverage for vaccines across the life course, including DTP3, the third dose of a pneumococcal conjugate vaccine (PCV3), the second dose of a measles-containing vaccine (MCV2), and the complete human papillomavirus vaccine series (HPVc).10, 28 These ambitious targets are important to prevent the resurgence of vaccine-preventable diseases and to foster strong and resilient immunisation and health-care systems that will serve as a platform for the introduction of new vaccines. The need for strong routine health systems to enable vaccine delivery was underscored during the pandemic and holds true today as new vaccines for malaria, dengue, Ebola virus, and other diseases are being developed and deployed.\u003c/p\u003e\u003cp\u003eTo advance universal childhood immunisation, a core principle of IA2030 is reliance on high-quality, targeted data to guide immunisation policies and programmes and to better measure progress extending vaccination coverage. Since 2000, a key source of vaccination data has been the WHO\u0026ndash;UNICEF Estimates of National Immunization Coverage (WUENIC),30 which uses a rules-based approach to provide annual routine vaccination coverage estimates for all WHO member states using expert judgement and qualitative knowledge to compile primary data from available sources. WUENIC estimates use country-reported and administrative data gathered through the WHO\u0026ndash;UNICEF Joint Reporting Form (JRF)30, 31, 32 and are informed by data from established household surveys, such as the Demographic and Health Surveys (DHS) Program and the Multiple Indicator Cluster Surveys. These estimates from WUENIC incorporate expert judgement and qualitative knowledge in their comprehensive compilation of primary data sources; however, the rules-based approach might lead to flat or noisy time trends, particularly in data-sparse locations, and is not able to account for uncertainty in the estimation process.32 Previous work from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) has applied a comprehensive statistical model to these data to systematically generate national estimates of vaccine coverage from 1980 to 2019.8 Because primary vaccination data can be inconsistent (ie, discrepant sampling methods and/or results),33 sparse (ie, few data in specific locations), and subject to bias (ie, systematic error imposed through biased sampling methodology),34, 35 the use of a statistical model to derive coverage estimates confers multiple advantages. These include the capacity to synthesise data from heterogeneous sources while accounting for the effects of discrepant data quality and types (eg, administrative \u003cem\u003evs\u003c/em\u003e survey) as well as the presence of systematic bias; to overcome data sparsity by leveraging time trends and other predictors; and to formally quantify estimation uncertainty.\u003c/p\u003e\u003cp\u003eHere, following the 50th anniversary year of EPI's founding and halfway through the decade of IA2030, we build on the framework of the previous GBD vaccine coverage study8 to generate updated estimates of vaccine coverage for 204 countries and territories from 1980 to 2023. We analyse progress over time in the coverage of key childhood vaccine-dose combinations and estimate trends in numbers of zero-dose individuals. We extend the previous GBD analysis to include the COVID-19 era, including many data sources delayed in reporting by the COVID-19 pandemic. We deploy new methods to account for the immediate and enduring effects of the COVID-19 pandemic in a unified framework, enhance estimation of the scale-up of newly introduced vaccines, and improve our estimation of counts of zero-dose children by modeling the first dose of the diphtheria, tetanus, and pertussis vaccine (DTP1) directly. Looking forward, we assess progress towards the IA2030 goals of 50% reduction in zero-dose children and 90% global coverage of select life-course vaccines in secondary analyses. First, building off an early framework developed by Causey and colleagues,18 we use a counterfactual approach to quantify the effect of the COVID-19 pandemic on the number of children who missed routine vaccinations between 2020 and 2023. Second, we evaluate progress needed to reach a 50% reduction in zero-dose children by 2030. Last, we forecast future DTP3, PCV3, and MCV2 coverage up to 2030 under three scenarios to show the range of plausible future trajectories. These comprehensive, updated estimates show progress and challenges in the effort to immunize against routine childhood diseases, providing crucial evidence to inform policies, programs, and investments aimed at ensuring that all children, everywhere, receive life-saving vaccinations.\u003c/p\u003e\u003cp\u003eThis manuscript was produced as part of the GBD Collaborator Network and in accordance with the GBD Protocol.36 Because newly available data and modified methods were used to update the full time series of estimates from 1980 to 2023, these results supersede all previous estimates.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003eOverview\u003c/p\u003e\u003cp\u003eTo generate coverage estimates of routine childhood vaccination in 204 countries and territories from 1980 to 2023, our core analysis followed the previous GBD methods,8 applying a multistep modelling approach using spatiotemporal Gaussian process regression (ST-GPR)37 and meta-regression\u0026mdash;Bayesian, regularised, trimmed (MR-BRT)38 tools to synthesise data collected primarily through the WHO\u0026ndash;UNICEF JRF31 and through household surveys. Annual country-specific coverage estimates were calculated for 11 childhood vaccine-dose combinations supported by EPI and administered via routine national immunisation programmes, including five vaccine-dose combinations from the four vaccines introduced in 1974 against diphtheria, tetanus, and pertussis (DTP1 and DTP3), measles (first dose of a measles-containing vaccine [MCV1]), polio (third dose of any form of polio vaccination [Pol3]), and tuberculosis (BCG)\u0026mdash;plus six vaccine-dose combinations rolled out in subsequent years (newer vaccines) targeting hepatitis B (third dose [HepB3]), \u003cem\u003eHaemophilus influenzae\u003c/em\u003e type b (third dose [Hib3]), rotavirus (complete series; RotaC), pneumococcus (PCV3), rubella (first dose of a rubella-containing vaccine [RCV1]), and measles (MCV2). Our core model adjusted for location-varying and time-varying bias in country-reported data from the JRF; leveraged data-dense evidence for specific locations, years, and vaccines to estimate coverage in instances of data sparsity; accounted for vaccine disruptions and country-specific years of vaccine introduction; and propagated uncertainty. Details regarding our innovations to the previous GBD methods and novel secondary analyses are provided in the sections below.\u003c/p\u003e\u003cp\u003eThis study complies with the Guidelines for Accurate and Transparent Health Estimates Reporting (GATHER) statement39. Analyses were done with R version 4.4.0. Statistical code used for estimation is publicly available on the Global Health Data Exchange.40\u003c/p\u003e\u003cp\u003eData\u003c/p\u003e\u003cp\u003eWe reviewed 8042 data sources between 1980 and 2023, of which 1085 unique sources were included in the analysis (representing 128 new sources compared with the previous GBD vaccine coverage study,8 including 37 new sources from 2020 to 2023 and 91 from 2019 and earlier). These sources comprise 64 546 country-year-vaccine-dose-specific datapoints, including 14 700 datapoints from vaccination-related household surveys (eg, DHS, Multiple Indicator Cluster Surveys, and other multicountry and country-specific surveys), 49 800 datapoints from administrative and official country-reported vaccine coverage data from the JRF and other sources, and supplemental data regarding stockout events, vaccine introductions to national immunisation programmes, and vaccine schedules, also reported through the JRF.41, 42, 43, 44 Data were catalogued and are publicly available on the Global Health Data Exchange.40 As in the previous study,8 we grouped coverage data by birth cohort (12\u0026ndash;23 months, 24\u0026ndash;35 months, 36\u0026ndash;47 months, 48\u0026ndash;59 months\u0026mdash;excluding cohorts younger than 1 year at the time of the survey) and\u0026mdash;to align survey-based data with country-reported data\u0026mdash;used county-specific vaccine schedules and vaccine introduction years to assign each cohort to the year of expected vaccine delivery.\u003c/p\u003e\u003cp\u003eModelling of administrative data bias\u003c/p\u003e\u003cp\u003eTo account for bias in country-reported coverage data,45 as in the GBD 2020 study, we used the MR-BRT modelling framework to assess differences in coverage within paired observations of survey data and original country-reported coverage from the same country-years. This bias was modelled as the ratio of survey data coverage to country-reported coverage, adjusting for the Healthcare Access and Quality (HAQ) Index (a composite index designed to assess and compare health-care access and quality),46 with the expectation that bias in reporting might vary based on the quality of health-care services. These MR-BRT bias predictions then served as a first-stage input for ST-GPR models. These bias adjustments were only applied directly for the original EPI vaccines; estimates for newer vaccines leveraged bias adjustments for the original EPI comparator vaccines through the ratio modelling process. New for this study, bias was directly modelled for both DTP1 and DTP3, rather than DTP3 only.\u003c/p\u003e\u003cp\u003eModelling of stockouts and other disruptions to vaccine coverage, including COVID-19\u003c/p\u003e\u003cp\u003eTo account for acute temporal disruptions (ie, drops) in coverage due to stockouts or other isolated events, we first modelled the magnitude of disruptions for vaccine-country-years with reported stockout events reported via the JRF42 or other identified disruption events. Disruption magnitudes were then included as a covariate in vaccine coverage modelling. New in this study, this covariate was devised by calculating the difference in coverage between country-reported data in vaccine-country-years identified as experiencing disruptions and counterfactual coverage estimates from models that excluded these vaccine-country-years. To account for disruptions due to COVID-19, also new to this study, we considered all vaccine-country-years for 2020 to 2023 as candidates for disruption events. New in this study, for vaccine-country-years in this period without available country-reported data, we imputed disruption magnitudes based on vaccine-year-specific distributions from locations with data.\u003c/p\u003e\u003cp\u003eVaccine coverage model\u003c/p\u003e\u003cp\u003eOur core analysis relied on modelling in ST-GPR to implement a multistep approach that produced location-specific annual estimates of vaccine coverage for 11 routine childhood vaccine-dose combinations in 204 countries and territories over the period of 1980 to 2023. ST-GPR is a stochastic modelling tool designed to synthesise heterogeneous inputs and flexibly smooth data over space and time, leveraging available high-density data to guide predictions in cases of absent or sparse data and to minimise prediction error.37 The model uses a three-stage approach, starting first with a regression incorporating covariates that might affect vaccine coverage. The second stage implements spatiotemporal smoothing, and the final stage uses a Gaussian Process regression to reduce error around high-precision data.\u003c/p\u003e\u003cp\u003eImprovements to this study include modifications to the modelling strategy for DTP. In\u003c/p\u003e\u003cp\u003eprevious GBD cycles, DTP3 coverage was modelled directly, and DTP1 was estimated with a continuation ratio ordinal regression approach.8 For GBD 2023, with increasing global focus on zero-dose children (proxied as those who have not received DTP1), we now model DTP1 directly and, to ensure internal consistency where DTP1 must be greater than DTP3, estimate DTP3 by modelling the DTP3/DTP1 ratio.\u003c/p\u003e\u003cp\u003eFor the directly modelled vaccines\u0026mdash;DTP1, MCV1, Pol3, and BCG\u0026mdash;country-specific and year-specific estimates of coverage were produced using ST-GPR models fit to bias-adjusted official country-reported data and survey data. ST-GPR models included covariates for the HAQ Index;46 mortality rates due directly to war and terror events as per data from Armed Conflict Location and Event Data, Uppsala Conflict Data Program, and Ethiopia's Tigray War data; and vaccine disruptions. We also used this approach to model the ratio of DTP3/DTP1 coverage (using bias-adjusted official country-reported data and survey for both numerator and denominator), which was multiplied post-hoc by our modelled estimates of DTP1 coverage by draw to calculate DTP3 coverage.\u003c/p\u003e\u003cp\u003eFor other vaccines, we modelled the ratio of coverage to that of one of the original EPI vaccines, using ST-GPR to allow for similarities and differences in these relationships across space and time. DTP3 served as the denominator, or reference vaccine, for modelling HepB3, Hib3, PCV3, and RotaC vaccine coverage ratios, given that it is typically given either as part of a combination vaccine and/or on the same schedule as these vaccines, whereas MCV1 was used as the reference vaccine for MCV2 and RCV1, to ensure that MCV2 coverage does not exceed MCV1 coverage, and because RCV1 is often delivered in a combination vaccine with MCV1. All ratios were constrained to be less than one, assuming newer vaccine coverage will be less than the original corresponding reference vaccine. New for GBD 2023, we estimated the scale-up of each newer vaccine ratio as a function of years since introduction. By explicitly modelling scale-up patterns and allowing these to vary by country and vaccine, we improved estimation in early years after introduction and in settings with sparse data. We fit predictive spline models of coverage ratios using MR-BRT in a geographical cascade: vaccine-specific models were first fit across all countries and territories, and the global model fits then served as priors for country-specific models. In this process, coverage ratios were modelled as a function of vaccine disruptions, years-since-introduction (fit using a spline), and a country-level random effect. The results of these spline models were used as first-stage estimates in subsequent ST-GPR coverage ratio models. Last, we multiplied the predicted coverage ratios from ST-GPR by the corresponding reference vaccine coverage to generate final estimates of coverage.\u003c/p\u003e\u003cp\u003eUncertainty was propagated by sampling 1000 random draws from the posterior distribution of each modelling step and conducting all subsequent calculations by draw. Results were summarised using the mean of all draws and the ordinal 2\u0026middot;5th and 97\u0026middot;5th percentile of draws to compute 95% uncertainty intervals (UIs). Super-regional and global aggregate estimates were calculated at the draw level as target population-weighted means.47, 48 In-sample and out-of-sample goodness of fit statistics were calculated. Coverage estimates were also compared with estimates from the previous GBD 2020 vaccine coverage study and estimates published by WUENIC in 2024.8, 49\u003c/p\u003e\u003cp\u003eSecondary and post-hoc analyses\u003c/p\u003e\u003cp\u003eTo understand the effect of the COVID-19 pandemic on childhood vaccination rates, we calculated vaccine coverage in a counterfactual (ie, alternative) scenario in which coverage was not affected by disruptions due to COVID-19 (COVID-free). This was done by removing post-hoc the disruption covariate effects from coverage estimates in 2020\u0026ndash;23. To account for potential disruptions that would have occurred even without the COVID-19 pandemic, we applied an adjustment scalar to the counterfactual estimates based on country-draw-level averages of disruption sizes for the preceding 5 years. This year range was chosen to reflect the most recent patterns in the occurrence and magnitude of disruptions.\u003c/p\u003e\u003cp\u003eTo assess progress towards the IA2030 goal of reducing the number of zero-dose children globally by half by 2030, compared with 2019, we considered a hypothetical scenario where all countries and territories reduce zero-dose children by 50% between these years (ie, equal contributions towards this goal). Using GBD population forecasts,50 we calculated the number of zero-dose children needed to be reached by 2030 and corresponding DTP1 coverage. To contextualise required DTP1 coverage increases, we calculated the 2023\u0026ndash;30 annualised rate of change (AROC) in DTP1 coverage needed for each country to meet this target. We then compared these to the distribution of AROCs across historical 7-year periods from 2000 to 2019 for all countries and territories.\u003c/p\u003e\u003cp\u003eTo predict progress towards IA2030's target of 90% coverage in 2030 for routine childhood vaccination across the life course, we adapted methods of Foreman and colleagues51 and GBD 2021 Forecasting Collaborators52 to forecast future coverage for DTP3, PCV3, and MCV2. We produced reference vaccine coverage forecasts for 2030 that capture the most likely reference future scenario. Forecasted DTP3 coverage for the reference scenario was estimated in a predictive modelling framework that leverages historic relationships between vaccine coverage estimates and the Socio-demographic Index (SDI), a composite indicator measuring a country's development status, with a logistic regression framework with SDI as the sole covariate.48 To show a plausible range of future coverage trajectories, we also produced alternative better and worse scenario forecasts based on historic rates of change. The better and worse scenario estimates were forecasts based on the 85th and 15th percentiles, respectively, of the distribution of past rates of change in coverage (in natural log space) between subsequent years. The historic distributions were calculated by draw, pulling from across countries and territories and all year pairs between 1980 and 2019, excluding years affected by the COVID-19 pandemic. Rates of change from more recent years were weighted more heavily in the distribution compared with those from earlier in the time series. Forecasts of PCV3/DTP3 and MCV2/MCV1 coverage ratios were produced using equivalent ratio modelling techniques as used in historical coverage estimation. We then multiplied by forecasted DTP3 and MCV1 estimates, respectively, for each scenario to calculate PCV3 and MCV2 coverage.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eTrends in vaccine coverage, 1980\u0026ndash;2019\u003c/p\u003e\n\u003cp\u003eBetween 1980 and 2019, global vaccine coverage for the original EPI vaccines\u0026mdash;BCG, MCV1, DTP1, DTP3, and Pol3\u0026mdash;approximately doubled, from 38\u0026middot;1% (95% UI 33\u0026middot;9\u0026ndash;42\u0026middot;3) in 1980 to 83\u0026middot;3% (82\u0026middot;7\u0026ndash;84\u0026middot;0) in 2019 for BCG, 37\u0026middot;1% (32\u0026middot;3\u0026ndash;41\u0026middot;6) to 83\u0026middot;1% (81\u0026middot;8\u0026ndash;84\u0026middot;3) for MCV1, 48\u0026middot;8% (44\u0026middot;1\u0026ndash;53\u0026middot;5) to 89\u0026middot;0% (88\u0026middot;3\u0026ndash;89\u0026middot;6) for DTP1, 39\u0026middot;6% (34\u0026middot;8\u0026ndash;44\u0026middot;3) to 80\u0026middot;9% (79\u0026middot;9\u0026ndash;81\u0026middot;9) for DTP3, and 42\u0026middot;4% (38\u0026middot;8\u0026ndash;46\u0026middot;4) to 79\u0026middot;6% (78\u0026middot;3\u0026ndash;81\u0026middot;0) for Pol3. Across this timeframe, this equates to an estimated 4\u0026middot;1 billion (4\u0026middot;07\u0026ndash;4\u0026middot;12) children vaccinated with BCG, 4\u0026middot;01 billion (3\u0026middot;98\u0026ndash;4\u0026middot;04) with MCV1, 4\u0026middot;48 billion (4\u0026middot;45\u0026ndash;4\u0026middot;51) with DTP1, 3\u0026middot;89 billion (3\u0026middot;85\u0026ndash;3\u0026middot;93) with DTP3, and 4\u0026middot;00 billion (3\u0026middot;96\u0026ndash;4\u0026middot;04) with Pol3 through routine immunization programs. However, these gains slowed or reversed between 2010 and 2019, even before COVID-19 pandemic-related disruptions in subsequent years. For MCV1, coverage declined between 2010 and 2019 for 100 of 204 countries and territories, with the biggest decrease in the Latin America and the Caribbean super-region (90\u0026middot;4% [88\u0026middot;6\u0026ndash;91\u0026middot;9] in 2010; 86\u0026middot;8% [85\u0026middot;0\u0026ndash;88\u0026middot;4] in 2019). For DTP1, DTP3, and Pol3, coverage declined between 2010 and 2019 for 100, 98, and 107 countries and territories, respectively, with the largest decreases similarly in Latin America and the Caribbean (DTP1 96\u0026middot;5% [96\u0026middot;0\u0026ndash;96\u0026middot;9] in 2010 and 85\u0026middot;4% [83\u0026middot;3\u0026ndash;87\u0026middot;3] in 2019; DTP3 89\u0026middot;8% [89\u0026middot;0\u0026ndash;90\u0026middot;6] in 2010 and 73\u0026middot;9% [70\u0026middot;9\u0026ndash;76\u0026middot;3] in 2019; Pol3 87\u0026middot;8% [86\u0026middot;9\u0026ndash;88\u0026middot;7] in 2010 and 76\u0026middot;9% [74\u0026middot;9\u0026ndash;78\u0026middot;6] in 2019). Of 158 countries and territories with BCG in the national immunisation schedule for all years between 2010 and 2019,41 coverage declined for 88 countries and territories over this period.\u003c/p\u003e\n\u003cp\u003eFor newer vaccines, coverage gains were more consistent. Coverage for HepB3 (80\u0026middot;1% [95% UI 79\u0026middot;0\u0026ndash;81\u0026middot;0]), Hib3 (70\u0026middot;7% [69\u0026middot;6\u0026ndash;71\u0026middot;7]), MCV2 (67\u0026middot;9% [66\u0026middot;7\u0026ndash;69\u0026middot;2]), and RCV1 (69\u0026middot;0% [68\u0026middot;0\u0026ndash;69\u0026middot;9]) had begun to approach that of the original EPI vaccines by 2019 (Fig. \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e). Global expansion of coverage for PCV3 and RotaC did not begin until the mid-2000s, but by 2019 global coverage reached 48\u0026middot;1% (47\u0026middot;3\u0026ndash;49\u0026middot;0) for PCV3 and 38\u0026middot;8% (38\u0026middot;2\u0026ndash;39\u0026middot;5) for RotaC.\u003c/p\u003e\n\u003cp\u003eTrends in zero-dose children, 1980\u0026ndash;2019\u003c/p\u003e\n\u003cp\u003eBetween 1980 and 2019, the global number of zero-dose children\u0026mdash;as represented by children younger than 1 year who have not received a DTP1 dose\u0026mdash;decreased by an estimated 74\u0026middot;9% (95% UI 72\u0026middot;1\u0026ndash;77\u0026middot;3), from 58\u0026middot;8 million (53\u0026middot;4\u0026ndash;64\u0026middot;2) to 14\u0026middot;7 million (13\u0026middot;8\u0026ndash;15\u0026middot;6; Fig. \u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e). Most of these decreases occurred at the beginning of EPI from 1980 to 1990, when zero-dose counts decreased by 55\u0026middot;3% (49\u0026middot;1\u0026ndash;60\u0026middot;5), and then following the launch of Gavi, the Vaccine Alliance when zero-dose counts decreased by another 35\u0026middot;4% (31\u0026middot;5\u0026ndash;39\u0026middot;5) from 2000 to 2010.\u003c/p\u003e\n\u003cp\u003eAt the super-regional level, the greatest reduction in the number of zero-dose children between 1980 and 2019 was in south Asia, with 19\u0026middot;5\u0026nbsp;million (95% UI 17\u0026middot;6\u0026ndash;21\u0026middot;0) fewer zero-dose children in 2019: an 89\u0026middot;3% (87\u0026middot;9\u0026ndash;90\u0026middot;4) decrease. In sub-Saharan Africa, DTP1 coverage nearly doubled between 1980 and 2019, from 42\u0026middot;3% (36\u0026middot;3\u0026ndash;48\u0026middot;7) to 78\u0026middot;2% (76\u0026middot;7\u0026ndash;79\u0026middot;8). However, the super-regional target population also grew by 125% during that time period, resulting in a more modest reduction of 1\u0026middot;41\u0026nbsp;million (0\u0026middot;168\u0026ndash;2\u0026middot;46) fewer zero-dose children in 2019 than 1980. In 1980, 53\u0026middot;5% (52\u0026middot;3\u0026ndash;54\u0026middot;7) of zero-dose children lived in just five countries: India, China, Indonesia, Pakistan, and Bangladesh. By 2019, most (52\u0026middot;8% [51\u0026middot;0\u0026ndash;54\u0026middot;3]) zero-dose children still lived in only seven countries: Nigeria, India, Ethiopia, Democratic Republic of the Congo, Brazil, Somalia, and Pakistan.\u003c/p\u003e\n\u003cp\u003eVaccine coverage trends, 2020\u0026ndash;23: effect of the COVID-19 pandemic\u003c/p\u003e\n\u003cp\u003eGlobal coverage for all original EPI vaccines declined following the onset of the COVID-19 pandemic. Substantial COVID-19 pandemic-related disruptions to global coverage for the original EPI vaccines began in 2020, generally increased in 2021 and 2022, then improved but did not fully resolve by 2023 (Fig. \u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e). The greatest decreases between 2019 (the final pre-pandemic comparator year) and 2023 were estimated for Pol3 coverage (2\u0026middot;8 percentage points [95% UI 0\u0026middot;7\u0026ndash;5\u0026middot;0]) and the smallest decreases for DTP1 (1\u0026middot;6 percentage points [0\u0026middot;5\u0026ndash;2\u0026middot;9]).\u003c/p\u003e\n\u003cp\u003eGlobal coverage for most of the newer vaccines continued to expand over the course of the COVID-19 pandemic, driven by both continued introductions and scale-up (Fig. \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e). The largest gains between 2019 (the year before the COVID-19 pandemic) and 2023 were estimated for PCV3 (14\u0026middot;3 percentage points [95% UI 12\u0026middot;9\u0026ndash;15\u0026middot;6]). All newer vaccines reached higher coverage levels in 2023 compared with 2019, except for HepB3. HepB3 is typically given as a part of a pentavalent vaccine with DTP, and global HepB3 coverage more closely mirrored DTP3 coverage and had similar disruptions during this time period. Global HepB3 coverage in 2023 remained 1\u0026middot;6 percentage points (0\u0026middot;2\u0026ndash;3\u0026middot;2) lower than that seen in 2019.\u003c/p\u003e\n\u003cp\u003eCompared with a counterfactual scenario absent COVID-related disruptions, global DTP3 coverage was 2\u0026middot;7 percentage points (95% UI 2\u0026middot;4\u0026ndash;3\u0026middot;2) lower in 2020, 4\u0026middot;2 percentage points (3\u0026middot;8\u0026ndash;4\u0026middot;6) lower in 2021, 2\u0026middot;3 percentage points (2\u0026middot;0\u0026ndash;2\u0026middot;9) lower in 2022, and 3\u0026middot;1 percentage points (2\u0026middot;7\u0026ndash;3\u0026middot;5) lower in 2023, with similar trends for MCV1, Pol3, and BCG (Fig. \u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e). The COVID-19 pandemic resulted in an estimated 15\u0026middot;6 million (14\u0026middot;4\u0026ndash;16\u0026middot;9) fewer children vaccinated with DTP3 globally between 2020 and 2023, 15\u0026middot;6 million (14\u0026middot;4\u0026ndash;17\u0026middot;0) fewer with MCV1, 15\u0026middot;9 million (15\u0026middot;0\u0026ndash;17\u0026middot;2) with Pol3, and 9\u0026middot;18 million (8\u0026middot;20\u0026ndash;10\u0026middot;2) with BCG. Although coverage continued to increase over 2020\u0026ndash;23 for newer vaccines, these gains did not keep pace with expectations absent the pandemic (Fig. \u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e). Among the newer vaccines, the largest pandemic impacts were estimated for RotaC, with 16\u0026middot;6\u0026nbsp;million (15\u0026middot;7\u0026ndash;17\u0026middot;7) fewer children vaccinated between 2020 and 2023 than if the pandemic had not occurred, followed by MCV2 (16\u0026middot;5\u0026nbsp;million [15\u0026middot;3\u0026ndash;18\u0026middot;0] fewer children), PCV3 (15\u0026middot;8\u0026nbsp;million [15\u0026middot;0\u0026ndash;16\u0026middot;8]), Hib3 (15\u0026middot;3\u0026nbsp;million [14\u0026middot;2\u0026ndash;16\u0026middot;5]), HepB3 (14\u0026middot;4\u0026nbsp;million [13\u0026middot;1\u0026ndash;15\u0026middot;7]), and RCV1 (13\u0026middot;4\u0026nbsp;million [12\u0026middot;2\u0026ndash;14\u0026middot;7]).\u003c/p\u003e\n\u003cp\u003eBoth the magnitude of COVID-19 pandemic-related disruptions to vaccine coverage and the degree of post-pandemic recovery varied by vaccine and super-region. Compared with the COVID-19-free counterfactual scenario, the largest single-year coverage disruptions were all estimated to have occurred in Latin America and the Caribbean, for PCV3 in 2023 and 2021, and DTP1 in 2021 (decreases of 11\u0026middot;6 percentage points [95% UI 9\u0026middot;6\u0026ndash;13\u0026middot;9], 11\u0026middot;2 percentage points [9\u0026middot;7\u0026ndash;14\u0026middot;1], and 11\u0026middot;2 percentage points [9\u0026middot;6\u0026ndash;12\u0026middot;7], respectively). Among other super-regions, greatest single-year disruptions were for RotaC in sub-Saharan Africa in 2022 (a decrease of 7\u0026middot;7 percentage points [7\u0026middot;3\u0026ndash;8\u0026middot;7]), RotaC in central Europe, eastern Europe, and central Asia in 2021 (7\u0026middot;2 percentage points [6\u0026middot;7\u0026ndash;7\u0026middot;8]), and PCV3 in North Africa and the Middle East in 2021 (7\u0026middot;0 percentage points [6\u0026middot;2\u0026ndash;8\u0026middot;4]). As of 2023, coverage of BCG, DTP1, DTP3, MCV1, and Pol3 had recovered to levels near expected without the COVID-19 pandemic (within 1 percentage point) only for BCG in sub-Saharan Africa and central Europe, eastern Europe, and central Asia; DTP1 in south Asia and central Europe, eastern Europe, and central Asia; DTP3 in central Europe, eastern Europe, and central Asia; MCV1 in central Europe, eastern Europe, and central Asia; and Pol3 in south Asia.\u003c/p\u003e\n\u003cp\u003eSub-Saharan Africa as a super-region saw the greatest cumulative disruptions to vaccine coverage across 2020 to 2023 in absolute numbers for RotaC, PCV3, and Pol3 (6\u0026middot;96\u0026nbsp;million [95% UI 6\u0026middot;73\u0026ndash;7\u0026middot;42], 5\u0026middot;31\u0026nbsp;million [5\u0026middot;09\u0026ndash;5\u0026middot;57], and 4\u0026middot;94\u0026nbsp;million [4\u0026middot;74\u0026ndash;5\u0026middot;19] fewer children vaccinated, respectively). The COVID-19 pandemic also resulted in an estimated 4\u0026middot;12\u0026nbsp;million (3\u0026middot;90\u0026ndash;4\u0026middot;38) additional children missing routine MCV1 vaccination in south Asia and 4\u0026middot;64\u0026nbsp;million (3\u0026middot;59\u0026ndash;5\u0026middot;64) in sub-Saharan Africa. Relative to target population size, cumulative disruptions were greatest in Latin America and the Caribbean, for PCV3, RotaC, and DTP3, with cumulative percent losses in children vaccinated of 9\u0026middot;4% (8\u0026middot;2\u0026ndash;10\u0026middot;6), 7\u0026middot;8% (6\u0026middot;7\u0026ndash;8\u0026middot;9), and 7\u0026middot;6% (6\u0026middot;5\u0026ndash;8\u0026middot;8), respectively. Other notable relative disruptions occurred in north Africa and the Middle East for PCV3 (a cumulative loss of 5\u0026middot;5% [5\u0026middot;1\u0026ndash;6\u0026middot;0]), sub-Saharan Africa for RotaC (a cumulative loss of 4\u0026middot;7% [4\u0026middot;5\u0026ndash;5\u0026middot;0]), and southeast Asia, east Asia, and Oceania for Pol3 (a cumulative loss of 4\u0026middot;3% [3\u0026middot;9\u0026ndash;4\u0026middot;6]). Greatest cumulative absolute and proportional COVID-19 pandemic disruptions tended to occur in Latin America and the Caribbean, sub-Saharan Africa, and south Asia.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTrends in zero-dose children, 2020\u0026ndash;23: impact of the COVID-19 pandemic and progress needed to reach the IA2030 target of 50% reduction by 2030\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe COVID-19 pandemic has reversed previous gains in reducing zero-dose children globally. As of 2023, there were 15\u0026middot;7\u0026nbsp;million (95% UI 14\u0026middot;6\u0026ndash;17\u0026middot;0) zero-dose children worldwide, compared with 14\u0026middot;7\u0026nbsp;million (13\u0026middot;8\u0026ndash;15\u0026middot;6) in 2019: a 2\u0026middot;9% (2\u0026middot;6\u0026ndash;3\u0026middot;2) increase. This reversal follows a long period of progress, during which global zero-dose counts decreased from 58\u0026middot;8\u0026nbsp;million (53\u0026middot;4\u0026ndash;64\u0026middot;2) in 1980 to 14\u0026middot;7\u0026nbsp;million (13\u0026middot;8\u0026ndash;15\u0026middot;6) in 2019. The global number of zero-dose children rose to 18\u0026middot;6\u0026nbsp;million (17\u0026middot;6\u0026ndash;20\u0026middot;0) in 2021 before declining, but still remaining above pre-pandemic levels in 2022 and 2023. To reach the IA2030 zero-dose target, the global number of zero-dose children would need to be halved from 2019 levels to 7\u0026middot;35\u0026nbsp;million (6\u0026middot;92\u0026ndash;7\u0026middot;82) by 2030. This would equate to increasing global DTP1 coverage from 87\u0026middot;4% (86\u0026middot;4\u0026ndash;88\u0026middot;3) in 2019 to 94\u0026middot;0% (93\u0026middot;6\u0026ndash;94\u0026middot;3) in 2023. Between 2020 and 2023, COVID-19 pandemic-related disruptions to DTP1 coverage resulted in a total of 12\u0026middot;8\u0026nbsp;million (11\u0026middot;7\u0026ndash;14\u0026middot;0) additional zero-dose children over these 4 years. South Asia was the only super-region whose DTP1 coverage in 2023 neared levels expected in absence of the pandemic (within 0\u0026middot;8 percentage points [\u0026ndash;0\u0026middot;9 to 1\u0026middot;9]). As of 2023, 51\u0026middot;1% (47\u0026middot;7\u0026ndash;53\u0026middot;6) of all zero-dose children lived in eight countries, primarily in sub-Saharan Africa and south Asia (Nigeria, India, Democratic Republic of the Congo, Ethiopia, Somalia, Sudan, Indonesia, and Brazil). Compared with 2019, this distribution reflects recent rising numbers of zero-dose children in Sudan and Indonesia and decreases in Pakistan due to rising coverage.\u003c/p\u003e\n\u003cp\u003eUnder a scenario in which all countries and territories contribute equally to the IA2030 zero-dose reduction goal, accounting for anticipated population changes, 51\u0026middot;2% (95% UI 35\u0026middot;9\u0026ndash;63\u0026middot;9) of the additional zero-dose children (8\u0026middot;34\u0026nbsp;million [7\u0026middot;12\u0026ndash;9\u0026middot;64]) needed to be reached by vaccination in 2030 compared with 2023 would live in eight countries: Nigeria, India, Democratic Republic of the Congo, Sudan, Somalia, Indonesia, Ethiopia, and Viet Nam. The largest absolute reductions in zero-dose children over 2023\u0026ndash;30 would be required in sub-Saharan Africa and south Asia (4\u0026middot;28\u0026nbsp;million [3\u0026middot;46\u0026ndash;5\u0026middot;10] and 1\u0026middot;33\u0026nbsp;million [1\u0026middot;07\u0026ndash;1\u0026middot;61], respectively). The super-regions of Latin America and the Caribbean and central Europe, eastern Europe, and central Asia have historically achieved the DTP1 coverage levels that would be needed to reach their IA2030 targets (91\u0026middot;9% [90\u0026middot;7\u0026ndash;92\u0026middot;9] and 98\u0026middot;0% [97\u0026middot;5\u0026ndash;98\u0026middot;4], respectively). For south Asia, 95\u0026middot;9% (95\u0026middot;5\u0026ndash;96\u0026middot;3) of DTP1 coverage would be required by 2030, 2\u0026middot;2 percentage points (1\u0026middot;8\u0026ndash;2\u0026middot;5) higher than the highest historical coverage. Sub-Saharan Africa would require 90\u0026middot;3% (89\u0026middot;6\u0026ndash;91\u0026middot;0) of DTP1 coverage, 12\u0026middot;1 percentage points (11\u0026middot;4\u0026ndash;12\u0026middot;8) higher than highest historical coverage in the super-region. Together, these two super-regions account for 65\u0026middot;1% (62\u0026middot;8\u0026ndash;68\u0026middot;6) of the total global reduction in zero-dose children required between 2023 and 2030.\u003c/p\u003e\n\u003cp\u003eAt the country level, 18 of 204 countries and territories had reached a 50% reduction in zero-dose children by 2023 (Fig. \u003cspan class=\"InternalRef\"\u003e4\u003c/span\u003e). Among those countries and territories with birth cohorts of at least 10 000, Tanzania, Jordan, and Malaysia had the greatest percentage reductions in zero-dose children, whereas Trinidad and Tobago, Ukraine, and Jordan had the greatest percentage point gains in DTP1 coverage. Conversely, compared with 2023 levels, 40 (20%) countries and territories require a more than 10 percentage point increase in DTP1 coverage by 2030, and these account for 62\u0026middot;4% (95% UI 52\u0026middot;4\u0026ndash;71\u0026middot;4) of the total reduction in global zero-dose children required over this time. Many countries and territories would need to substantially outpace historical trends to reach 2030 zero-dose targets. Of 186 countries and territories not meeting this target by 2023, only 18 (10%) require a future AROC below the median of historical AROCs, and nearly half (80 [43%]) would need to exceed the 80th percentile of historical AROCs (Fig. \u003cspan class=\"InternalRef\"\u003e4\u003c/span\u003eC). Among the eight countries needed to contribute the largest reductions in zero-dose children (4\u0026middot;22 million [51\u0026middot;2%] of 8\u0026middot;34 million), seven would need to exceed the 80th percentile of past DTP1 AROCs (Somalia, Sudan, Democratic Republic of the Congo, Viet Nam, Nigeria, Ethiopia, and Indonesia), six would need to exceed the 90th percentile (Somalia, Sudan, Democratic Republic of the Congo, Viet Nam, Nigeria, and Ethiopia), five would need to exceed the 95th percentile (Somalia, Sudan, Democratic Republic of the Congo, Viet Nam, and Nigeria), and two would need to exceed the 99th percentile (Somalia and Sudan). For these countries, improvements in DTP1 coverage would need to outpace almost any gain that any country in the world has achieved since 2000. As of 2019, 38 countries and territories had achieved 99% DTP1 coverage or greater, but this number decreased to 24 countries and territories by 2023.\u003c/p\u003e\n\u003cp\u003eForecasting progress towards IA2030 90% coverage targets for life-course vaccines\u003c/p\u003e\n\u003cp\u003eTo assess progress towards the IA2030 goals of 90% global coverage for life-course vaccines, we forecasted vaccine coverage for three scenarios (reference, better, and worse). By 2030, globally, vaccine coverage under the reference scenario is forecasted to reach 81\u0026middot;3% (95% UI 79\u0026middot;5\u0026ndash;82\u0026middot;7) for DTP3 (2\u0026middot;4 percentage points [0\u0026middot;6\u0026ndash;3\u0026middot;8] higher than in 2023), 71\u0026middot;1% (69\u0026middot;6\u0026ndash;72\u0026middot;5) for PCV3 (8\u0026middot;7 percentage points [7\u0026middot;1\u0026ndash;10\u0026middot;1] higher than in 2023), and 76\u0026middot;0% (73\u0026middot;7\u0026ndash;78\u0026middot;1) for MCV2 (5\u0026middot;2 percentage points [2\u0026middot;8\u0026ndash;7\u0026middot;2] higher than in 2023; Fig. \u003cspan class=\"InternalRef\"\u003e5\u003c/span\u003e). In contrast, under the worse scenario, global vaccine coverage could decline between 2023 and 2030 to 68\u0026middot;9% (66\u0026middot;9\u0026ndash;70\u0026middot;4) for DTP3, 59\u0026middot;3% (57\u0026middot;4\u0026ndash;60\u0026middot;9) for PCV3, and 62\u0026middot;7% (60\u0026middot;1\u0026ndash;65\u0026middot;1) for MCV2. Alternatively, under the better scenario, global vaccine coverage could increase to 91\u0026middot;2% (89\u0026middot;4\u0026ndash;92\u0026middot;7) for DTP3, 85\u0026middot;7% (84\u0026middot;0\u0026ndash;87\u0026middot;3) for PCV3, and 85\u0026middot;3% (83\u0026middot;1\u0026ndash;87\u0026middot;1) for MCV2. Even under the better scenario, only DTP3 coverage (historically higher than the more recently introduced MCV2 and PCV3) is forecasted to reach 90% global coverage. However, reference scenario forecasts varied substantially by GBD super-region.\u003c/p\u003e\n\u003cp\u003e85 of 204 countries and territories are estimated to have reached 90% coverage by 2023 for DTP3, 56 countries for PCV3, and 57 countries for MCV2. Under the reference scenario, an additional 23 countries and territories are forecasted to reach 90% coverage for DTP3 by 2030 (108 of 204 total), 27 countries for PCV3 (83 of 204 total), and 34 countries for MCV2 (91 of 204 total). Notably, only the high-income super-region is expected to reach or retain at least 90% coverage for the three life-course vaccines by 2030 under the reference scenario. Under the better scenario, these achievements would improve to 186 of 204 countries and territories for DTP3, 171 countries for PCV3, and 161 countries for MCV2. Under the worse alternative scenario, all countries and territories that had achieved 90% coverage for DTP3, PCV3, and MCV2 by 2023 would drop below this target by 2030.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cdiv id=\"Sec5\" class=\"Section2\"\u003e\u003ch2\u003eOverview of main findings\u003c/h2\u003e\u003cp\u003eThe first five decades of EPI have fundamentally transformed the landscape of global health through the vaccination of more than four billion children, a doubling of coverage for the original EPI vaccines, the successful introduction and scale-up of new life-saving vaccines, and a three-quarters reduction in the number of zero-dose children since 1980. In recent years, however, this progress has stalled and in some areas of the world reversed\u0026mdash;a period of stagnation that began in the decade preceding the COVID-19 pandemic for the original EPI vaccines. We estimate that the COVID-19 pandemic resulted in tens of millions of additional children missing doses from across these 11 routine childhood vaccines since 2020, including an additional 12\u0026middot;8\u0026nbsp;million zero-dose children, compared with expectations had the pandemic not occurred. Although vaccine coverage in 2023 remained lower than expected in the absence of the pandemic, there are signs of recovery across many vaccines and super-regions, thanks to the concerted efforts of local, national, regional, and global vaccine advocates.\u003c/p\u003e\u003cp\u003eFive decades on, therefore, the promise of EPI\u0026mdash;to extend the life-saving benefits of vaccines to all children around the world\u0026mdash;has been only partially fulfilled. As these results underscore, global vaccine coverage targets cannot be met without transformational improvements in equity.\u003c/p\u003e\u003c/div\u003e\n\u003ch3\u003eChallenges to sustaining and improving on EPI's successes\u003c/h3\u003e\n\u003cp\u003eDespite the remarkable public health successes achieved around the globe by routine childhood vaccination over the past 50 years, efforts to preserve and extend these gains face considerable challenges. Inequalities in coverage, including large numbers of children who remain unvaccinated, persist across and within regions, countries and territories, and communities.8, 9, 14, 15, 53, 54 As the present findings highlight\u0026mdash;although steep drops in counts of unvaccinated zero-dose children took place over the past five decades in nearly all regions of the world\u0026mdash;these successes were not matched in sub-Saharan Africa, where declines were considerably less pronounced. Zero-dose numbers even increased in some areas during certain periods: in sub-Saharan Africa and south Asia during the 1990s, and in Latin America and the Caribbean and in central Europe, eastern Europe, and central Asia after 2010. As of 2023, more than 50% of the world's zero-dose children lived in just eight countries, characterised variously by weak health systems, large birth cohorts, geographical isolation, erosion of vaccine confidence, and exposure to conflict.9 Indeed, our results show that Sudan was close to reaching a 90% DTP1 coverage in 2019, but with civil war arising in 2023 as per Armed Conflict Location and Event Data, coverage nearly halved. Our estimates reflect complex interactions between these interrelated factors and underscore the need for targeted interventions tailored to each circumstance.\u003c/p\u003e\n\u003ch3\u003eEffect of the COVID-19 pandemic\u003c/h3\u003e\n\u003cp\u003eStarting in 2020, much of the long-term progress achieved in the global campaign to reduce mortality and morbidity through routine immunisation was halted or reversed during the massive global upheaval caused by the COVID-19 pandemic and has not fully recovered since. The crisis and its cascading effects placed extraordinary pressure on health systems and providers, immunisation supply chains, and health spending, which\u0026mdash;combined with physical distancing and stay-at-home measures\u0026mdash;severely limited the ability of health workers and those in need of care to provide and access services.55 Other studies found during the height of the pandemic that coverage inequalities within regions grew during the pandemic.56 Even after these measures were lifted, the effects of the COVID-19 pandemic had been ongoing. Even as late as 2023, 84% of countries and territories were still reporting some disruption to health services, and immunisation ranked third highest in terms of services disrupted.11, 57 Our estimates show that between 2019 and 2023, global numbers of zero-dose children rose to their highest levels in 2021 at 18\u0026middot;6\u0026nbsp;million, with counts in 2023 remaining at 15\u0026middot;7\u0026nbsp;million, 989 000 more than in 2019. In addition, global coverage decreased for all the original EPI vaccines between 2019 and 2023, with the greatest declines occurring in 2021.\u003c/p\u003e\u003cp\u003eOur analysis suggests that the COVID-19 pandemic, along with disruptions in immunisation services due to recent conflicts, has resulted in tens of millions of additional children globally missing routine vaccines since 2020, increasing their risk for preventable disease and death. In 2022, 33 countries and territories reported sizeable measles outbreaks, compared with 22 countries and territories in 2021. In addition, increasing numbers of wild-type polio cases were reported in Pakistan and Afghanistan, and new outbreaks of wild-type polio occurred in Malawi and Mozambique in 2024. A resurgence of diphtheria was also reported, with outbreaks in Bangladesh, Nepal, Nigeria, Pakistan, Venezuela, and Yemen.58, 59 These disease trends were already on the rise before the COVID-19 pandemic60 and reflect long-standing inequalities in vaccine coverage but pose a global risk, including to high-income countries and territories where coverage has stagnated or declined in recent years.\u003c/p\u003e\u003cp\u003eDespite these challenges, the effect of the COVID-19 pandemic on vaccination coverage could have been even greater. In a previous analysis using partial-year data from the first months of the pandemic, Causey and colleagues estimated 2020 global DTP3 coverage at approximately 76\u0026middot;7%, which is 7\u0026middot;7 percentage points lower than was expected in the absence of the pandemic.18 In contrast, with the benefit of time to account for delayed reporting from many countries and data sources, our present estimates using more complete data indicate that global DTP3 coverage in 2020 was 78\u0026middot;5%, or just 2\u0026middot;7 percentage points lower than expected without the pandemic. The mitigation of the pandemic's influence on vaccine coverage reflects the tremendous efforts of vaccinators worldwide and the concerted and coordinated efforts on the part of immunisation organisations to continue the delivery of essential health services in extremely challenging circumstances.61, 62\u003c/p\u003e\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e\u003ch2\u003eChallenges and opportunities in different zero-dose populations\u003c/h2\u003e\u003cp\u003eDue to the known challenges to vaccine delivery posed by poverty, lack of accessibility, and the presence of civil or regional conflicts,53, 54, 63, 64 research and policy work focused on zero-dose children has concentrated primarily on the urban poor or those living in remote or conflict-affected areas.65, 66, 67 Given the consistently strong relationship between mothers' education and whether their children are immunised,54, 68 there is also growing awareness of the effect of the social construct of gender on vaccination coverage.15 The low societal status of women\u0026mdash;manifesting in a lack of resources, agency, and power\u0026mdash;is increasingly shown to be one of the most universal factors adversely affecting equitable childhood immunisation.68, 69, 70, 71 Gender inequalities and socioeconomic factors\u0026mdash;including migration status, poverty, ethnicity or caste, access to family planning, and geographical setting\u0026mdash;intersect to depress childhood immunisation outcomes for under-resourced populations.68, 72\u003c/p\u003e\u003cp\u003eCountries and territories with the highest zero-dose burdens face a demographic double challenge: although the global birth cohort is projected to shrink by 1\u0026middot;6% globally between 2023 and 2030,73 many high-burden countries and territories will have substantial growth in their vaccination target populations. Nigeria, Ethiopia, and Democratic Republic of the Congo\u0026mdash;which collectively contain 26\u0026middot;8% (95% UI 24\u0026middot;2\u0026ndash;28\u0026middot;8) of global zero-dose children as of 2023\u0026mdash;will see birth cohorts expand by 16\u0026middot;1%, 10\u0026middot;6%, and 5\u0026middot;9%, respectively, during this period. These demographic trends translate directly into increased resource requirements for achieving vaccination targets or even maintaining present coverage levels. These population pressures, combined with existing health system constraints, underscore the need for vaccination strategies that scale more rapidly than population growth in these settings, including enhanced outreach services, simplified delivery models, and innovative workforce approaches. Beyond population growth challenges, even successful 50% reductions in zero-dose counts across all countries and territories would still leave 26 countries with less than 90% DTP1 coverage in 2030, reflecting the magnitude of current inequalities in coverage.\u003c/p\u003e\u003cp\u003eThe diversity of challenges and barriers leading to the failure to immunise varies broadly from country to country and community to community, highlighting the need for new and tailored solutions.65, 66, 67, 74 Strategies such as the Identify-Reach-Monitor-Measure-Advocate framework75 have been proposed as a way to develop and deliver community-specific plans to reach zero-dose children. Some key strategies that have yielded improved vaccine uptake include awareness and education, communication, mobility of vaccination units, community engagement, motivational incentives, positive reinforcement, and assurance of vaccine safety.76, 77 These efforts must be supported by strong evidence and data, including robust, timely, and local estimates of coverage and a better understanding of the location and characteristics of zero-dose children within each country.78\u003c/p\u003e\u003c/div\u003e\n\u003ch3\u003eVaccine hesitancy\u003c/h3\u003e\n\u003cp\u003eAlthough some of the COVID-19 pandemic-specific challenges to vaccination have receded, several key challenges persist\u0026mdash;including increasing disparities in resource-constrained, conflict-affected, or politically-volatile countries and territories;79, 80 intensification of migration and displacement; and climate-related crises.10, 11 An additional challenge to progress has been the threat of growing vaccine hesitancy. Deriving from many complex origins, vaccine misinformation81, 82 and scepticism were already challenges before the pandemic, identified by WHO in 2019 as one of the ten leading threats to global health.23, 83, 84 The COVID-19 pandemic, which in many areas bred declining trust in public health institutions85 and polarised opinions about the necessity and safety of vaccination against COVID-19,82 has had varying effects on public perceptions regarding the importance of routine childhood vaccination and willingness to vaccinate. A 2023 global analysis reported that vaccine hesitancy prevalence ranged from a low of 13\u0026middot;3% in the WHO region of the Americas to a high of 27\u0026middot;9% in the Eastern Mediterranean region,86 and even higher in select African countries.87 In the USA, most parents remained convinced of the benefits and effectiveness of childhood vaccines between 2020 and 2022, with confidence levels ranging from 89\u0026middot;5% to 92\u0026middot;5%, although concerns about vaccine safety and side-effects increased over that time,88 and kindergarten vaccine exemption rates in 2023\u0026ndash;24 were the highest ever reported.89\u003c/p\u003e\u003cp\u003eAlthough overall confidence in routine childhood immunisation remains relatively high, the COVID-19 pandemic clearly exposed a vein of public distrust regarding health policy that is likely to influence public perception of childhood vaccines into the future.84 Strategies to improve vaccine confidence include bolstering scientific literacy to protect against an erosion of trust in science, implementing targeted public health campaigns to promote routine childhood immunisation, including community input in scientific research and policy making, engaging with community and religious leaders as advocates for immunisation, and elevating and equipping health-care providers\u0026mdash;who remain the most trusted voices on vaccination\u0026mdash;to have impactful conversations about decisions to immunise.25, 83, 84\u003c/p\u003e\n\u003ch3\u003eLooking forward to WHO's Immunization Agenda 2030 targets\u003c/h3\u003e\n\u003cp\u003eTo track progress in vaccination across the life course, IA2030 targets include halving the global number of zero-dose children and achieving 90% global coverage of DTP3, PCV3, MCV2, and HPVc by 2030 (HPVc was not included in the present analysis due to the lack of currently available data). These targets were ambitious at the time of their creation and present even greater challenges now, following the effect of the COVID-19 pandemic on global vaccination rates. For many countries and territories, the IA2030 targets might be achievable, but might require acceleration of progress. In the countries, territories, and super-regions with the largest numbers of non-immunised and under-immunised children, achieving these targets would require extraordinary improvements in vaccination coverage. By 2023, numbers of zero-dose children remained higher than in 2019 in all super-regions except south Asia. Our forecasts indicate that achieving the ambitious IA2030 goal of 90% global coverage by 2030 for each of the life-course vaccines DTP3, PCV3, and MCV228 is also unlikely. Moreover, coverage disparities seen in 2023 for DTP3 and MCV2 will persist in 2030, with coverage rates in sub-Saharan Africa remaining substantially below other super-regions.\u003c/p\u003e\u003cp\u003eOur analysis suggests similar challenges in meeting zero-dose reduction goals. Even if optimistic forecast scenarios were to be achieved, or if all countries and territories were to meet zero-dose reduction targets, these results suggest that substantial geographical disparities will persist in 2030\u0026mdash;particularly for DTP3 and MCV2. For PCV3, coverage disparities will lessen due to ongoing introductions and scale-up, though would nevertheless persist even in the better scenario.\u003c/p\u003e\u003cp\u003eThe success of the first 50 years of EPI has only been possible due to broad and sustained cooperation at all levels, from local health workers to national immunisation programmes to regional and global partnerships. At the global level, WHO coordinates and provides vaccination guidance for all countries and territories and plays a central role in data collection. For example, this study relies on 49 710 vaccine-country-years of data reported by country offices that were collected, collated, and reported annually by WHO through the JRF,31 and these estimates additionally benefit from contextual insights regarding these coverage data generated by WUENIC.49 Gavi supports qualifying countries and territories in strengthening their immunisation programmes, and currently provides vaccines for routine immunisation in 54 countries and territories while they work towards more sustained domestic financing strategies.90 This report shows the substantial scaling up of newer vaccines in low-income and middle-income countries and territories, and Gavi has had a central role in supporting these country-led introductions. The US Agency for International Development (USAID) has also had a key role in monitoring vaccine coverage in low-income and middle-income countries through the DHS, which provide a major source of population-based data about vaccination rates at national and local scales. This study includes data from 313 DHS sources, which represent over half (50\u0026middot;2%) of all survey data sources included from low-income and middle-income countries.\u003c/p\u003e\u003cp\u003eWith recent shifts in the global immunisation funding environment\u0026mdash;including the large-scale termination of USAID-supported programmes, announced cuts to US funding for Gavi and WHO, and broader reductions in global commitments to developmental assistance for health\u0026mdash;91, 92, 93, 94 the historical and future progress of vaccination programmes is at risk. With reduced fiscal space, any further new vaccine introductions are in jeopardy, vaccination coverage rates might decrease, and the risk of vaccine-preventable disease is heightened. In this time of risk, accurate estimates of vaccine coverage become even more important. With the closure of the DHS programme, strategic and coordinated efforts to assess coverage through targeted surveys and support for country immunisation data systems will be needed.\u003c/p\u003e\u003cp\u003eChildhood immunisation is an outstanding investment with excellent returns in health and economic benefits, across countries and territories of all income levels.95, 96, 97, 98 Proposed reductions in immunisation spending are likely to disproportionally affect low-income and middle-income countries, but high-income countries and territories are also likely to incur health-care costs associated with new and more frequent disease outbreaks.99, 100 Europe saw its highest number of measles cases in 2024 since 1997, and the first measles-related death in the last decade in the USA occurred in an unvaccinated child as part of a measles outbreak in Texas in early 2025.101 Without concerted efforts to bolster immunisation rates in all countries and territories, these risks will continue to increase.102\u003c/p\u003e\u003cp\u003eDue to ongoing uncertainty about the final scope and magnitude of proposed funding cuts, the effects of these decisions are not considered in our forecasts of the IA2030 life-course vaccines. However, if these proposed funding cuts are fully implemented, the forecasts presented here, which already show that global coverage is not on track to reach the IA2030 targets, are likely to be too optimistic. Similarly, the scenario of equal contribution presented here with all countries and territories contributing proportionally to 50% zero-dose reduction targets becomes even more unlikely given the disproportionate effects of additional funding constraints. Nevertheless, it is important to note that any gains in coverage and reduction of existing disparities\u0026mdash;even if they fall short of the ambitious goals set by IA2030\u0026mdash;would still result in massive public health gains. Each percentage point increase in global vaccination coverage represents protection for millions of additional children against deadly diseases. This perspective does not diminish the importance of ambitious targets, but rather emphasises the substantial value of continued, incremental progress in all settings.\u003c/p\u003e\u003cp\u003eLimitations\u003c/p\u003e\u003cp\u003eOur present estimates of routine childhood vaccination coverage are limited by various methodological considerations. First, although we applied models designed to adjust for bias in vaccine coverage data, we were not able to account for all potential sources of bias. Displaced or otherwise disenfranchised individuals might be under-represented in the data. Survey data might not accurately capture effects such as migration, catch-up vaccination, and differential survival by immunisation status across the age cohorts on which we based our analyses. Both surveys and country-reported data might be limited in their ability to assess immunisation rates in conflict-affected areas, leading to potential overestimation in the absence of data from these locations and time periods. Reporting of surveys and country-reported data was in many instances delayed by the COVID-19 pandemic; while the timing of this study has allowed for catch-up in reporting, decreases in survey participation rates and other forms of reporting biases during that time might have also occurred and are not reflected in this study. Data that relied on parental or observer recall are subject to recall bias, which we did not to adjust for, based on evidence indicating highly variable effects of recall bias on coverage estimates.103, 104, 105 We were also not able to systematically account for methodological variability across surveys. We provide statistical uncertainty from our modelling framework to reflect confidence in the reported coverage values. Although ST-GPR and MR-BRT partially mitigate the limitations of data sparsity in select locations, estimates in such areas might show greater uncertainty. In this analysis, we produce estimates for all national locations included in the GBD 2023 study, including those for which data are sparse and estimates are uncertain. This approach follows the principles of the GBD study,38 which prioritise comprehensive comparisons and recognise that the absence of an estimate often results in the exclusion of that location from strategic planning and policy decisions. Although we aim to select covariates plausibly linked to vaccination coverage, our models do not allow for potential interactions between covariates such as SDI and disruption magnitude or conflict. Due to the multistep nature of ST-GPR, these limitations are most likely to affect data-sparse locations, where estimates are more heavily informed by covariates and regional trends. Similarly, although our modelled estimates of administrative bias allow variation in bias over time where multiple overlapping coverage observations from survey and country-reported data are available, estimates of trends in bias might be less reliable in data-sparse locations, or where abrupt discontinuities in administrative reporting methodology occur (eg, when countries switch to using electronic systems such as DHIS2 for ascertaining vaccine delivery counts).\u003c/p\u003e\u003cp\u003eSecond, our reliance on DTP1 coverage as a measure of zero-dose children, although standard practice,9, 106 could overestimate the number of those who do not receive any childhood vaccinations, as children might in some cases receive other vaccinations even after missing DTP1. Similarly, our understanding of trends in zero-dose children rely on estimates and forecasts of populations. Following standard GBD practices, we did not account for uncertainty in these population estimates, and the uncertainty intervals for zero-dose and other counts included here thus represent uncertainty only in the associated coverage estimates. The uncertainty intervals for these count-based estimates, therefore, may underestimate the true degree of uncertainty in these measures.\u003c/p\u003e\u003cp\u003eThird, our analysis does not include data on vaccinations that take place outside EPI-designated routine childhood immunisation schedules, such as vaccinations administered in limited immunisation campaigns targeting specific populations or administered through private markets (except for selected private vaccinations in China, which are included in our analysis). Due to a lack of comprehensive data, our analysis does not account for catch-up vaccination activities, including global efforts through WHO's Big Catch-Up initiative to reach children who missed routine immunisations during the COVID-19 pandemic.58 Although age-specific survey data can provide some insight into catch-up vaccination, comprehensive administrative data are not available to inform such models. Additional efforts are needed to collect data and develop analytic methods to estimate coverage across all ages, including the effect of catch-up activities. Even so, catch-up activities represent a stop-gap measure that cannot replace improvements to routine health-care services. Our results show that disruptions due to COVID-19 have had long-lasting and persistent effects on routine services, which serve as the foundation for strong immunisation programmes.\u003c/p\u003e\u003cp\u003eFourth, our analysis estimates the size of the effect of the COVID-19 pandemic on vaccine coverage by first estimating coverage in the absence of stockouts or any other disruptions to coverage. We then assume that, absent the COVID-19 pandemic, each country would have had the average degree of coverage disruption due to stockouts or other factors, as was observed from 2015 to 2019. This year range was selected to try to reflect the most recent patterns in disruptions, but nevertheless it is challenging to disentangle the ongoing historical trends from the impacts of the COVID-19 pandemic, and it is not necessarily the case that recent disruption trends would have continued apace. In particular, for countries and territories where large disruptions were common before the COVID-19 pandemic or coverage levels were changing rapidly, we may overestimate or underestimate COVID-19 pandemic-related impacts. Therefore, we have presented the results of this post-hoc analysis in aggregate at super-region and global levels only. In this counterfactual estimation, we do not account for the effect of delays in the introduction of new vaccines that might have occurred due to the COVID-19 pandemic. For these newer vaccines, it is therefore likely that we might underestimate the global effect of the pandemic.\u003c/p\u003e\u003cp\u003eFifth, we imputed disruption estimates for countries and territories without country-reported data during the COVID-19 pandemic, using vaccine-specific and year-specific distributions of disruption magnitudes from locations with available data. As our results show, however, actual disruption magnitudes varied widely. Our results in these country-vaccine-years might thus reflect either overestimation or underestimation of actual disruptions. In particular, many high-income countries and territories have incomplete data reporting during the COVID-19 pandemic and estimates of COVID-19 pandemic-related disruptions in these locations should be interpreted with caution.\u003c/p\u003e\u003cp\u003eSixth, our process for estimating coverage of newer vaccines first as ratios relative to a reference vaccine (DTP3 for HepB3, Hib3, PCV3, and RotaC, and MCV1 for MCV2 and RCV1) constrains our estimates of these newer vaccines to be lower than that of their respective reference vaccines. For vaccines given in combination with the reference vaccine (eg, RCV1 and MCV1, or Hib3 and DTP3), or where these constraints are implied by definition (eg, MCV2\u0026thinsp;\u0026lt;\u0026thinsp;MCV1, or DTP3\u0026thinsp;\u0026lt;\u0026thinsp;DTP1), this assumption is appropriate. PCV and rotavirus vaccines, are typically given on the same schedule as DTP; however, coverage could exceed that of DTP3 in rare cases, particularly in the setting of intensive scale-up or vaccine-specific disruptions to DTP3 coverage. Future improvements to this work could consider independent modelling of PCV3 and/or RotaC coverage.\u003c/p\u003e\u003cp\u003eAlthough not a focus of the present analysis, characterising within-country differences in coverage is also important. Assessing coverage by crucial sociodemographic factors\u0026mdash;eg, by geography at subnational scales, wealth, education, women's status, refugee status, and race and ethnicity\u0026mdash;can help identify persistent disparities in routine childhood vaccination masked by the national overview estimates presented here. Similarly, although HPVc is one of IA2030's 90% life-course vaccine coverage targets and has been recommended globally by WHO since 2009,107 we were not able to generate estimates or forecasts of HPVc coverage due to the lack of currently available survey data in most settings. Additional work will be needed to generate coverage estimates for HPVc and other vaccines not included here, using rigorous statistical frameworks that can leverage both survey and administrative data sources. In this report, we did not measure rates of under-vaccinated children, those who have received only some but not all vaccine doses in their vaccination schedule, or assess patterns in the timeliness of vaccination. Comprehensive estimates of the full spectrum of vaccination, beyond the coverage metrics presented here, would improve understanding of population susceptibility and risks of disease outbreaks.\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eOver the past 50 years, EPI has achieved extraordinary success in the urgent public health campaign to immunise the world's children against life-threatening diseases. The next 50 years will require sustained efforts at global, regional, national, and community levels to successfully preserve and extend existing gains. Enduring coverage inequities and the persistent effects of the COVID-19 pandemic only serve to underscore the importance of advancing routine childhood vaccination, one of the most powerful public health interventions known.\u003c/p\u003e\u003cp\u003eCurrent trends and forecasts, along with proposed reductions to global immunisation financing, suggest that reaching the ambitious goals of IA2030\u0026mdash;aimed at reducing mortality and morbidity from vaccine-preventable diseases for everyone, everywhere\u0026mdash;is unlikely to be realised unless the global community redoubles its commitment to equitable and universal vaccination strategies. Effective programmes and policies must integrate vaccination services into revitalised primary health-care systems, focus on context-specific and community-driven immunisation strategies, increase and optimise investment in vaccination, and prioritise community-led approaches to build vaccine confidence. Yet these present and future challenges should be met with firm confidence in the power and promise of vaccination, rooted in the successes of the past 50 years of EPI. It is important that the global health community embrace our shared responsibility and whole-heartedly reaffirm our collective commitment to routine childhood vaccination to deliver on the promise of EPI to provide all people, everywhere the opportunity to live full and healthy lives.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eContributors\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eShaunt Papelian\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDeclarations of interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe author has no conflict of interest\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNo funding was received for conducting this study\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData sharing\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study follows the Guidelines for Accurate and Transparent Health Estimates Reporting (GATHER). To download the estimates produced in these analyses, please visit the Global Health Data Exchange website at https://ghdx.healthdata.org/record/ihme-data/gbd-2023-vaccinationcoverage-1980-2030.\u0026nbsp;\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eWHO. WorldHealthAssembly.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWHO. Essentialprogrammeonimmunization.\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.who.int/teams/immunization-vaccines-and-biologicals/essentialprogramme-on-immunization\u003c/span\u003e\u003cspan address=\"https://www.who.int/teams/immunization-vaccines-and-biologicals/essentialprogramme-on-immunization\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e(accessedJuly30,2024).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eShattock AJ, Johnson HC, Sim SY. Contribution of vaccination to improved survival and health: modelling 50 years of the Expanded Programme on Immunization. Lancet. 2024;403:2307\u0026ndash;16.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eInstitute for Health Metrics and Evaluation. Financing global health 2023: the future of health financing in the post-pandemic era. Institute for Health Metrics and Evaluation; 2024.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSim SY, Watts E, Constenla D, Brenzel L, Patenaude BN. Return on investment from immunization against 10 pathogens in 94 low- and middle-income countries, 2011\u0026ndash;30. Health Aff (Millwood). 2020;39:1343\u0026ndash;53.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eJohns Hopkins University, International Vaccine Access Center. Methodology report: Decade of Vaccines Economics (DOVE) return on investment analysis. International Vaccine Access Center; 2019.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eOzawa S, Clark S, Portnoy A, Grewal S, Brenzel L, Walker DG. Return on investment from childhood immunization in low- and middleincome countries, 2011\u0026ndash;20. Health Aff (Millwood). 2016;35:199\u0026ndash;207.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGBD2020,Release1,VaccineCoverageCollaborators.Measuringroutinechildhoodvaccinationcoveragein204countriesandterritories,1980\u0026ndash;2019:asystematicanalysisfortheGlobalBurdenofDiseaseStudy2020,release1.Lancet2021;398:503\u0026ndash;21.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWHO. Progress and challenges with achieving universal immunization coverage: 2023 WHO/UNICEF Estimates of National Immunization Coverage (WUENIC). World Health Organization; 2024.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWHO. Immunization agenda 2030: a global strategy to leave no one behind. World Health Organization; 2020.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eIA2030 Coordination Group. IA2030technicalprogressreport2023.ImmunizationAgenda2030,2023.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eColom\u0026eacute;-Hidalgo M, Donado Campos J, Gil de Miguel \u0026Aacute;. Monitoring inequality changes in full immunization coverage in infants in Latin America and the Caribbean. Rev Panam Salud Publica. 2020;44:e56.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGuzman-Holst A, DeAntonio R, Prado-Cohrs D, Juliao P. Barriers to vaccination in Latin America: a systematic literature review. Vaccine. 2020;38:470\u0026ndash;81.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLocal Burden of Disease Vaccine Coverage Collaborators. Mapping routine measles vaccination in low- and middle-income countries. Nature. 2021;589:415\u0026ndash;19.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eChopra M, Bhutta Z, Chang Blanc D. Addressing the persistent inequities in immunization coverage. Bull World Health Organ. 2020;98:146\u0026ndash;48.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eIslam MR, Rahman MM, Rahman MS, Abe SK, Akmatov MK, Hashizume M. Trends and projections of age-appropriate vaccination coverage in 41 low- and middle- income countries in Asia and subSaharan Africa, 2000\u0026ndash;2030. Front Public Health. 2024;12:1371258.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWendt A, Santos TM, Cata-Preta BO. Exposure of zero-dose children to multiple deprivation: analyses of data from 80 low- and middle-income countries. Vaccines (Basel). 2022;10:1568.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCausey K, Fullman N, Sorensen RJD. Estimating global and regional disruptions to routine childhood vaccine coverage during the COVID-19 pandemic in 2020: a modelling study. Lancet. 2021;398:522\u0026ndash;34.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLassi ZS, Naseem R, Salam RA, Siddiqui F, Das JK. The impact of the COVID-19 pandemic on immunization campaigns and programs: a systematic review. Int J Environ Res Public Health. 2021;18:988.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eUNICEF.Morethan117 millionchildrenatriskofmissingoutonmeaslesvaccines,asCOVID-19surges.April13. 2020.\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.unicef.org/press-releases/more-117-million-children-risk-missingout-measles-vaccines-covid-19-surges(accessedJuly30,2024\u003c/span\u003e\u003cspan address=\"https://www.unicef.org/press-releases/more-117-million-children-risk-missingout-measles-vaccines-covid-19-surges(accessedJuly30,2024\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWHO.COVID-19pandemicfuelslargestcontinuedbackslideinvaccinationsinthreedecades.July15. 2022.\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.who.int/news/item/15-07-2022-covid-19-pandemic-fuels-largest-continuedbackslide-in-vaccinations-in-three-decades(accessedJuly30,2024\u003c/span\u003e\u003cspan address=\"https://www.who.int/news/item/15-07-2022-covid-19-pandemic-fuels-largest-continuedbackslide-in-vaccinations-in-three-decades(accessedJuly30,2024\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWagenaar BH, Augusto O, Beste J. The 2014\u0026ndash;2015 Ebola virus disease outbreak and primary healthcare delivery in Liberia: timeseries analyses for 2010\u0026ndash;2016. PLoS Med. 2018;15:e1002508.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eEagan RL, Larson HJ, de Figueiredo A. Recent trends in vaccine coverage and confidence: a cause for concern. Hum Vaccin Immunother. 2023;19:2237374.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eUNICEF. The state of the world\u0026rsquo;s children 2023: for every child, vaccination. UNICEF Innocenti, Global Office of Research and Foresight; 2023.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWHO. The Global Vaccine Action Plan 2011\u0026ndash;2020. Review and lessons learned. World Health Organization; 2019.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWHO. Implementing the Immunization Agenda 2030: a framework for action through coordinated planning, monitoring \u0026amp; evaluation, ownership \u0026amp; accountability, and communications \u0026amp; advocacy. World Health Organization; 2021.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eUN. Ensure healthy lives and promote well-being for all at all ages. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://sdgs.un.org/goals/goal3#targets_and_indicators\u003c/span\u003e\u003cspan address=\"https://sdgs.un.org/goals/goal3#targets_and_indicators\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (accessed April 10, 2025).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eIA2030 Scorecard. Immunization Agenda 2030 scorecard: overview dashboard. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://scorecard.immunizationagenda2030.org\u003c/span\u003e\u003cspan address=\"https://scorecard.immunizationagenda2030.org\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (accessed Nov 19, 2024).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCata-Preta BO, Santos TM, Mengistu T, Hogan DR, Barros AJD, Victora CG. Zero-dose children and the immunisation cascade: understanding immunisation pathways in low and middle-income countries. Vaccine. 2021;39:4564\u0026ndash;70.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWHO. WHO/UNICEF estimates of national immunization coverage. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.who.int/teams/immunization-vaccines-and-biologicals/immunization-analysis-and-insights/global-monitoring/immunization-coverage/who-unicef-estimates-of-national-immunization-coverage\u003c/span\u003e\u003cspan address=\"https://www.who.int/teams/immunization-vaccines-and-biologicals/immunization-analysis-and-insights/global-monitoring/immunization-coverage/who-unicef-estimates-of-national-immunization-coverage\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (accessed July 30, 2024).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWHO. WHO/UNICEF joint reporting process. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.who.int/teams/immunization-vaccines-and-biologicals/immunization-analysis-and-insights/global-monitoring/who-unicef-joint-reporting-process\u003c/span\u003e\u003cspan address=\"https://www.who.int/teams/immunization-vaccines-and-biologicals/immunization-analysis-and-insights/global-monitoring/who-unicef-joint-reporting-process\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (accessed July 30, 2024).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBurton A, Monasch R, Lautenbach B, et al. WHO and UNICEF estimates of national infant immunization coverage: methods and processes. Bull World Health Organ. 2009;87:535\u0026ndash;41.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePond B, Bekele A, Mounier-Jack S, Teklie H, Getachew T. Estimation of Ethiopia's immunization coverage\u0026mdash;20years of discrepancies. BMC Health Serv Res. 2021;21(suppl 1):587.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMboussou F, Kada S, Danovaro-Holliday MC, et al. Status of routine immunization coverage in the World Health Organization african region three years into the COVID-19 pandemic. Vaccines (Basel). 2024;12:168.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eRau C, L\u0026uuml;decke D, Dumolard LB, et al. Data quality of reported child immunization coverage in 194 countries between 2000 and 2019. PLOS Glob Public Health. 2022;2:e0000140.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eInstitute for Health Metrics and Evaluation. Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) protocol. June 4. 2024. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.healthdata.org/sites/default/files/2024-06/GBD%20Protocol%20060424.pdf\u003c/span\u003e\u003cspan address=\"https://www.healthdata.org/sites/default/files/2024-06/GBD%20Protocol%20060424.pdf\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (accessed July 30, 2024).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGBD 2021 Diseases and Injuries Collaborators. Global incidence, prevalence, years lived with disability (YLDs), disability-adjusted life-years (DALYs), and healthy life expectancy (HALE) for 371 diseases and injuries in 204 countries and territories and 811 subnational locations, 1990\u0026ndash;2021: a systematic analysis for the Global Burden of Disease Study 2021. Lancet. 2024;403:2133\u0026ndash;61.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eZheng P, Barber R, Sorensen RJD, Murray CJL, Aravkin AY. Trimmed constrained mixed effects models: formulations and algorithms. J Comput Graph Stat. 2021;30:544\u0026ndash;56.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eStevens GA, Alkema L, Black RE, et al. Guidelines for accurate and transparent health estimates reporting: the GATHER statement. Lancet. 2016;388:e19\u0026ndash;23.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eIHME. Global Burden of Disease Study 2023. (GBD 2023) routine childhood vaccination coverage estimates and forecasts 1980\u0026ndash;2030. May 15, 2025. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://ghdx.healthdata.org/record/ihme-data/gbd-2023-vaccination-coverage-1980-2030\u003c/span\u003e\u003cspan address=\"https://ghdx.healthdata.org/record/ihme-data/gbd-2023-vaccination-coverage-1980-2030\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (accessed June 2, 2025).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWHO. Immunization data: vaccination schedule. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://immunizationdata.who.int/global?topic=Vaccinationschedule\u0026amp;location=\u003c/span\u003e\u003cspan address=\"https://immunizationdata.who.int/global?topic=Vaccinationschedule\u0026amp;location=\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (accessed Aug 9, 2024).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWHO. Immunization data: vaccine supply and logistics. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://immunizationdata.who.int/global/wiise-detail-page/vaccine-supply-and-logistics\u003c/span\u003e\u003cspan address=\"https://immunizationdata.who.int/global/wiise-detail-page/vaccine-supply-and-logistics\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (accessed Jan 30, 2025).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWHO. Immunization data: vaccine introduction. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://immunizationdata.who.int/global?topic=Vaccineintroduction\u0026amp;location=\u003c/span\u003e\u003cspan address=\"https://immunizationdata.who.int/global?topic=Vaccineintroduction\u0026amp;location=\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (accessed Aug 9, 2024).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWHO. Immunization data. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://immunizationdata.who.int/global\u003c/span\u003e\u003cspan address=\"https://immunizationdata.who.int/global\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (accessed Jan 30, 2025).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBloland P, MacNeil A. Defining \u0026amp; assessing the quality, usability, and utilization of immunization data. BMC Public Health. 2019;19:380.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGBD 2019 Healthcare Access and Quality Collaborators. Assessing performance of the Healthcare Access and Quality Index, overall and by select age groups, for 204 countries and territories, 1990\u0026ndash;2019: a systematic analysis from the Global Burden of Disease Study 2019. Lancet Glob Health. 2022;10:e1715\u0026ndash;43.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMurray CJ, Ezzati M, Flaxman AD, et al. GBD 2010: design, definitions, and metrics. Lancet. 2012;380:2063\u0026ndash;66.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGBD 2021 Demographics Collaborators. Global age-sex-specific mortality, life expectancy, and population estimates in 204 countries and territories and 811 subnational locations, 1950\u0026ndash;2021, and the impact of the COVID-19 pandemic: a comprehensive demographic analysis for the Global Burden of Disease Study 2021. Lancet. 2024;403:1989\u0026ndash;2056.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWHO, UNICEF. WUENIC trends. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://worldhealthorg.shinyapps.io/wuenic-trends/\u003c/span\u003e\u003cspan address=\"https://worldhealthorg.shinyapps.io/wuenic-trends/\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (accessed April 4, 2025).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eVollset SE, Goren E, Yuan C-W, et al. Fertility, mortality, migration, and population scenarios for 195 countries and territories from 2017 to 2100: a forecasting analysis for the Global Burden of Disease Study. Lancet. 2020;396:1285\u0026ndash;306.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eForeman KJ, Marquez N, Dolgert A, et al. Forecasting life expectancy, years of life lost, and all-cause and cause-specific mortality for 250 causes of death: reference and alternative scenarios for 2016-40 for 195 countries and territories. Lancet. 2018;392:2052\u0026ndash;90.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGBD 2021 Forecasting Collaborators. Burden of disease scenarios for 204 countries and territories, 2022\u0026ndash;2050: a forecasting analysis for the Global Burden of Disease Study 2021. Lancet. 2024;403:2204\u0026ndash;56.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWHO. Explorations of inequality: childhood immunization. World Health Organization; 2018.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAli HA, Hartner A-M, Echeverria-Londono S, et al. Vaccine equity in low and middle income countries: a systematic review and meta-analysis. Int J Equity Health. 2022;21:82.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eShet A, Carr K, Danovaro-Holliday MC, et al. Impact of the SARS-CoV-2 pandemic on routine immunisation services: evidence of disruption and recovery from 170 countries and territories. Lancet Glob Health. 2022;10:e186\u0026ndash;94.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLai X, Zhang H, Pouwels KB, Patenaude B, Jit M, Fang H. Estimating global and regional between-country inequality in routine childhood vaccine coverage in 195 countries and territories from 2019 to 2021: a longitudinal study. EClinicalMedicine. 2023;60:102042.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWHO. Fourth round of the global pulse survey on continuity of essential health services during the COVID-19 pandemic: November 2022\u0026ndash;January 2023. World Health Organization; 2023.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWHO, UNICEF. Gavi, the Vaccine Alliance. The Big Catch-up: an essential immunization recovery plan for 2023 and beyond. World Health Organization; 2023.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLubanga AF, Bwanali AN, Kangoma M, et al. Addressing the re-emergence and resurgence of vaccine-preventable diseases in Africa: a health equity perspective. Hum Vaccin Immunother. 2024;20:2375081.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWHO. Measles: global situation. Nov 27. 2019. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.who.int/emergencies/disease-outbreak-news/item/2019-DON211\u003c/span\u003e\u003cspan address=\"https://www.who.int/emergencies/disease-outbreak-news/item/2019-DON211\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (accessed April 10, 2025).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWHO. Immunization as an essential health service: guiding principles for immunization activities during the COVID-19 pandemic and other times of severe disruption. World Health Organization; 2020.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDixit SM, Sarr M, Gueye DM, et al. Addressing disruptions in childhood routine immunisation services during the COVID-19 pandemic: perspectives from Nepal, Senegal and Liberia. BMJ Glob Health. 2021;6:e005031.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGrundy J, Biggs B-A. The impact of conflict on immunisation coverage in 16 countries. Int J Health Policy Manag. 2019;8:211\u0026ndash;21.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBangura JB, Xiao S, Qiu D, Ouyang F, Chen L. Barriers to childhood immunization in sub-Saharan Africa: a systematic review. BMC Public Health. 2020;20:1108.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eNandy R, Rees H, Bernson J, Digre P, Rowley E, McIlvaine B. Tackling inequities in immunization outcomes in urban contexts. Jan 12, 2018. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://global.comminit.com/content/tackling-inequities-immunization-outcomes-urban-contexts\u003c/span\u003e\u003cspan address=\"https://global.comminit.com/content/tackling-inequities-immunization-outcomes-urban-contexts\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (accessed Oct 29, 2024).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eOkwo-Bele J-M, Conner R, McIlvaine B, Rowley E, Bernson J. Tackling inequities in immunization outcomes in conflict contexts. Jan 12, 2018. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.comminit.com/global/content/tackling-inequities-immunization-outcomes-conflict-contexts\u003c/span\u003e\u003cspan address=\"https://www.comminit.com/global/content/tackling-inequities-immunization-outcomes-conflict-contexts\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (accessed Oct 29, 2024).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLevine O, Lemango ET, Bernson J, Gurley N, Rowley E, McIlvaine B. Tackling inequities in immunization outcomes in remote rural contexts. Jan 12, 2018. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://global.comminit.com/content/tackling-inequities-immunization-outcomes-remote-rural-contexts\u003c/span\u003e\u003cspan address=\"https://global.comminit.com/content/tackling-inequities-immunization-outcomes-remote-rural-contexts\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (accessed Oct 29, 2024).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eFeletto M, Sharkey A, Rowley E et al. A gender lens to advance equity in immunization. July 5, 2019. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://global.comminit.com/content/gender-lens-advance-equity-immunization\u003c/span\u003e\u003cspan address=\"https://global.comminit.com/content/gender-lens-advance-equity-immunization\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (accessed Oct 31, 2024).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKalbarczyk A, Brownlee N, Katz E. Of money and men: a scoping review to map gender barriers to immunization coverage in low- and middle-income countries. Vaccines (Basel). 2024;12:625.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eFeletto M, Sharkey A. The influence of gender on immunisation: using an ecological framework to examine intersecting inequities and pathways to change. BMJ Glob Health. 2019;4:e001711.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMerten S, Martin Hilber A, Biaggi C, et al. Gender determinants of vaccination status in children: evidence from a meta-ethnographic systematic review. PLoS ONE. 2015;10:e0135222.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eEquity Reference Group for Immunization. Tackling inequities in immunisation outcomes: a gender lens. January, 2019. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://drive.google.com/file/d/1KowBaWNtYAsW42MJBjRVSDoe_QCbmB4-/view?usp=embed_facebook\u003c/span\u003e\u003cspan address=\"https://drive.google.com/file/d/1KowBaWNtYAsW42MJBjRVSDoe_QCbmB4-/view?usp=embed_facebook\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (accessed Oct 31, 2024).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGBD 2021 Fertility and Forecasting Collaborators. Global fertility in 204 countries and territories, 1950\u0026ndash;2021, with forecasts to 2100: a comprehensive demographic analysis for the Global Burden of Disease Study 2021. Lancet. 2024;403:2057\u0026ndash;99.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eEquity Reference Group for Immunization. ERG advocacy brief. 2019. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://drive.google.com/file/d/1VpuVX85RWd_vq6FJ4lcmCnPOYJp1AhuM/view?usp=sharing\u0026amp;usp=embed_facebook\u003c/span\u003e\u003cspan address=\"https://drive.google.com/file/d/1VpuVX85RWd_vq6FJ4lcmCnPOYJp1AhuM/view?usp=sharing\u0026amp;usp=embed_facebook\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (accessed Oct 26, 2024).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGavi, the Vaccine Alliance. Guidance on use of Gavi support to reach zero dose children and missed communities. Gavi, 2021.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTuckerman J, Kaufman J, Danchin M. Effective approaches to combat vaccine hesitancy. Pediatr Infect Dis J. 2022;41:e243\u0026ndash;45.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ede Koning R, Gonzalez Utrilla M, Spanaus E, Moore M, Lomazzi M. Strategies used to improve vaccine uptake among healthcare providers: a systematic review. Vaccine X. 2024;19:100519.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHogan D, Gupta A. Why reaching zero-dose children holds the key to achieving the Sustainable Development Goals. Vaccines (Basel). 2023;11:781.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWorld Bank Group. World Bank Group strategy for fragility, conflict, and violence 2020\u0026ndash;2025. Feb 26. 2020. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.worldbank.org/en/topic/fragilityconflictviolence/publication/world-bank-group-strategy-for-fragility-conflict-and-violence-2020-2025\u003c/span\u003e\u003cspan address=\"https://www.worldbank.org/en/topic/fragilityconflictviolence/publication/world-bank-group-strategy-for-fragility-conflict-and-violence-2020-2025\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (accessed Nov 22, 2024).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWorld Bank Group. Classification of fragile and conflict-affected situations. June 28. 2024. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.worldbank.org/en/topic/fragilityconflictviolence/brief/classification-of-fragile-and-conflict-affected-situations\u003c/span\u003e\u003cspan address=\"https://www.worldbank.org/en/topic/fragilityconflictviolence/brief/classification-of-fragile-and-conflict-affected-situations\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (accessed Nov 22, 2024).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKata A. A postmodern Pandora's box: anti-vaccination misinformation on the internet. Vaccine. 2010;28:1709\u0026ndash;16.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ede Figueiredo A, Temfack E, Tajudeen R, Larson HJ. Declining trends in vaccine confidence across sub-Saharan Africa: a large-scale cross-sectional modeling study. Hum Vaccin Immunother. 2023;19:2213117.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWHO. Ten threats to global health in 2019. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.who.int/news-room/spotlight/ten-threats-to-global-health-in-2019\u003c/span\u003e\u003cspan address=\"https://www.who.int/news-room/spotlight/ten-threats-to-global-health-in-2019\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (accessed Nov 4, 2024).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eOpel DJ, Brewer NT, Buttenheim AM, et al. The legacy of the COVID-19 pandemic for childhood vaccination in the USA. Lancet. 2023;401:75\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eRobert Wood Johnson Foundation. The public's perspective on the United States public health system. May 1. 2021. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.rwjf.org/content/rwjf-web/us/en/insights/our-research/2021/05/the-publics-perspective-on-the-united-states-public-health-system.html\u003c/span\u003e\u003cspan address=\"https://www.rwjf.org/content/rwjf-web/us/en/insights/our-research/2021/05/the-publics-perspective-on-the-united-states-public-health-system.html\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (accessed Nov 13, 2024).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAbenova M, Shaltynov A, Jamedinova U, Semenova Y. Worldwide child routine vaccination hesitancy rate among parents of children aged 0\u0026ndash;6 years: a systematic review and meta-analysis of cross-sectional studies. Vaccines (Basel). 2023;12:31.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAnjorin AA, Odetokun IA, Abioye AI, et al. Will Africans take COVID-19 vaccination? PLoS ONE. 2021;16:e0260575.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eShah MD, Szilagyi PG, Shetgiri R, et al. Trends in parents' confidence in childhood vaccines during the COVID-19 pandemic. Pediatrics. 2022;150:e2022057855.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSeither R, Yusuf OB, Dramann D, et al. Coverage with selected vaccines and exemption rates among children in kindergarten\u0026mdash;United States, 2023\u0026ndash;24 school year. MMWR Morb Mortal Wkly Rep. 2024;73:925\u0026ndash;32.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGavi, the Vaccine Alliance. April,. Vaccine funding guidelines. 2023. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.gavi.org/sites/default/files/programmes-impact/Vaccine_FundingGuidelines.pdf\u003c/span\u003e\u003cspan address=\"https://www.gavi.org/sites/default/files/programmes-impact/Vaccine_FundingGuidelines.pdf\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (accessed April 4, 2025).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eThe White House. Reevaluating and realigning United States Foreign Aid. Jan 20. 2025. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.whitehouse.gov/presidential-actions/2025/01/reevaluating-and-realigning-united-states-foreign-aid/\u003c/span\u003e\u003cspan address=\"https://www.whitehouse.gov/presidential-actions/2025/01/reevaluating-and-realigning-united-states-foreign-aid/\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (accessed April 4, 2025).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eThe White House. Withdrawing the United States from the World Health Organization. Jan 20. 2025. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.whitehouse.gov/presidential-actions/2025/01/withdrawing-the-united-states-from-the-worldhealth-organization/\u003c/span\u003e\u003cspan address=\"https://www.whitehouse.gov/presidential-actions/2025/01/withdrawing-the-united-states-from-the-worldhealth-organization/\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (accessed April 4, 2025).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGovernment of the Netherlands. Foreign trade and development minister Reinette Klever: Dutch interests at the heart of development policy. Feb 20. 2025. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.government.nl/latest/news/2025/02/20/minister-reinette-klever-dutch-interests-at-the-heart-of-development-policy\u003c/span\u003e\u003cspan address=\"https://www.government.nl/latest/news/2025/02/20/minister-reinette-klever-dutch-interests-at-the-heart-of-development-policy\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (accessed April 4, 2025).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWalker P. Dismay as UK poised to cut funding for global vaccination group Gavi. Feb 10, 2025. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.theguardian.com/society/2025/feb/10/dismay-as-uk-poised-to-cut-funding-for-global-vaccination-group-gavi\u003c/span\u003e\u003cspan address=\"https://www.theguardian.com/society/2025/feb/10/dismay-as-uk-poised-to-cut-funding-for-global-vaccination-group-gavi\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (accessed April 4, 2025).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eZhou F, Jatlaoui TC, Leidner AJ, et al. Health and economic benefits of routine childhood immunizations in the era of the vaccines for children program\u0026mdash;United States, 1994\u0026ndash;2023. MMWR Morb Mortal Wkly Rep. 2024;73:682\u0026ndash;85.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eOzawa S, Clark S, Portnoy A, Grewal S, Brenzel L, Walker DG. Return on investment from childhood immunization in low- and middle-income countries, 2011\u0026ndash;20. Health Aff (Millwood). 2016;35:199\u0026ndash;207.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSim SY, Watts E, Constenla D, Brenzel L, Patenaude BN. Return on investment from immunization against 10 pathogens in 94 low- and middle-income countries, 2011\u0026ndash;30. Health Aff (Millwood). 2020;39:1343\u0026ndash;53.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLindstrand A, Cherian T, Chang-Blanc D, Feikin D, O'Brien KL. The world of immunization: achievements, challenges, and strategic vision for the next decade. J Infect Dis. 2021;224(suppl 2):S452\u0026ndash;67.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWHO. European Region reports highest number of measles cases in more than 25 years\u0026mdash;UNICEF, WHO/Europe. March 13. 2025. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.who.int/europe/news/item/13-03-2025-european-region-reports-highest-number-of-measles-cases-in-more-than-25-years---unicef--who-europe\u003c/span\u003e\u003cspan address=\"https://www.who.int/europe/news/item/13-03-2025-european-region-reports-highest-number-of-measles-cases-in-more-than-25-years---unicef--who-europe\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (accessed April 4, 2025).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eNandi A, Shet A. Why vaccines matter: understanding the broader health, economic, and child development benefits of routine vaccination. Hum Vaccin Immunother. 2020;16:1900\u0026ndash;04.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWHO. Measles\u0026mdash;United States of America. March 27. 2025. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.who.int/emergencies/disease-outbreak-news/item/2025-DON561\u003c/span\u003e\u003cspan address=\"https://www.who.int/emergencies/disease-outbreak-news/item/2025-DON561\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (accessed April 4, 2025).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWHO. The impact of suspensions and reductions in health official development assistance on health systems. World Health Organization; 2025.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDansereau E, Brown D, Stashko L, Danovaro-Holliday MC. A systematic review of the agreement of recall, home-based records, facility records, BCG scar, and serology for ascertaining vaccination status in low and middle-income countries. Gates Open Res. 2020;3:923.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMiles M, Ryman TK, Dietz V, Zell E, Luman ET. Validity of vaccination cards and parental recall to estimate vaccination coverage: a systematic review of the literature. Vaccine. 2013;31:1560\u0026ndash;68.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMurray CJL, Shengelia B, Gupta N, Moussavi S, Tandon A, Thieren M. Validity of reported vaccination coverage in 45 countries. Lancet. 2003;362:1022\u0026ndash;27.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eJones CE, Danovaro-Holliday MC, Mwinnyaa G, et al. Routine vaccination coverage\u0026mdash;worldwide, 2023. MMWR Morb Mortal Wkly Rep. 2024;73:978\u0026ndash;84.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWHO. WHO position paper on human papillomavirus (HPV) vaccines. World Health Organization; 2009.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-7340665/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7340665/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSince its inception in 1974, the Essential Programme on Immunization (EPI) has achieved remarkable success, averting the deaths of an estimated 154 million children worldwide through routine childhood vaccination. However, more recent decades have seen persistent coverage inequities and stagnating progress, which have been further amplified by the COVID-19 pandemic. In 2019, WHO set ambitious goals for improving vaccine coverage globally through the Immunization Agenda 2030 (IA2030). Now halfway through the decade, understanding past and recent coverage trends can help inform and reorient strategies for approaching these aims in the next 5 years.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eBased on the Global Burden of Diseases, Injuries, and Risk Factors Study 2023, this study provides updated global, regional, and national estimates of routine childhood vaccine coverage from 1980 to 2023 for 204 countries and territories for 11 vaccine-dose combinations recommended by WHO for all children globally. Employing advanced modeling techniques, this analysis accounts for data biases and heterogeneity and integrates new methodologies to model vaccine scale-up and COVID-19 pandemic-related disruptions. To contextualize historic coverage trends and gains still needed to achieve the IA2030 coverage targets, we supplement these results with several secondary analyses: (1) we assess the effect of the COVID-19 pandemic on vaccine coverage; (2) we forecast coverage of select life-course vaccines up to 2030; and (3) we analyze progress needed to reduce the number of zero-dose children by half between 2023 and 2030.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFindings\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eOverall, global coverage for the original EPI vaccines against diphtheria, tetanus, and pertussis (first dose [DTP1] and third dose [DTP3]), measles (MCV1), polio (Pol3), and tuberculosis (BCG) nearly doubled from 1980 to 2023. However, this long-term trend masks recent challenges. Coverage gains slowed between 2010 and 2019 in many countries and territories, including declines in 21 of 36 high-income countries and territories for at least one of these vaccine doses (excluding BCG, which has been removed from routine immunization schedules in some countries and territories). The COVID-19 pandemic exacerbated these challenges, with global rates for these vaccines declining sharply since 2020, and still not returning to pre-COVID-19 pandemic levels as of 2023. Coverage for newer vaccines developed and introduced in more recent years, such as immunizations against pneumococcal disease (PCV3) and rotavirus (complete series; RotaC) and a second dose of the measles vaccine (MCV2), saw continued increases globally during the COVID-19 pandemic due to ongoing introductions and scale-ups, but at slower rates than expected in the absence of the pandemic. Forecasts to 2030 for DTP3, PCV3, and MCV2 suggest that only DTP3 would reach the IA2030 target of 90% global coverage, and only under an optimistic scenario. The number of zero-dose children, proxied as children younger than 1 year who do not receive DTP1, decreased by 74·9% (95% uncertainty interval 72·1–77·3) globally between 1980 and 2019, with most of those declines reached during the 1980s and the 2000s. After 2019, counts of zero-dose children rose to a COVID 19-era peak of 18·6 million (17·6–20·0) in 2021. Most zero-dose children remain concentrated in conflict-affected regions and those with various constraints on resources available to put towards vaccination services, particularly sub-Saharan Africa. As of 2023, more than 50% of the 15·7 million (14·6–17·0) global zero-dose children resided in just eight countries (Nigeria, India, Democratic Republic of the Congo, Ethiopia, Somalia, Sudan, Indonesia, and Brazil), emphasizing persistent inequities.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eInterpretation\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eOur estimates of current vaccine coverage and forecasts to 2030 suggest that achieving IA2030 targets, such as halving zero-dose children compared with 2019 levels and reaching 90% global coverage for life-course vaccines DTP3, PCV3, and MCV2, will require accelerated progress. Substantial increases in coverage are necessary in many countries and territories, with those in sub-Saharan Africa and south Asia facing the greatest challenges. Recent declines will need to be reversed to restore previous coverage levels in Latin America and the Caribbean, especially for DTP1, DTP3, and Pol3. These findings underscore the crucial need for targeted, equitable immunisation strategies. Strengthening primary health-care systems, addressing vaccine misinformation and hesitancy, and adapting to local contexts are essential to advancing coverage. COVID-19 pandemic recovery efforts, such as WHO's Big Catch-Up, as well as efforts to bolster routine services must prioritize reaching marginalized populations and target subnational geographies to regain lost ground and achieve global immunisation goals.\u003c/p\u003e","manuscriptTitle":"Global and national trends in childhood vaccination coverage from 1980 to 2023 with forecasts to 2030","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-08-12 12:57:00","doi":"10.21203/rs.3.rs-7340665/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"a91d1d2b-5f85-4d44-8b21-63df964f54e1","owner":[],"postedDate":"August 12th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-08-12T12:57:03+00:00","versionOfRecord":[],"versionCreatedAt":"2025-08-12 12:57:00","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7340665","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7340665","identity":"rs-7340665","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}