Global Spatiotemporal Analysis in Hepatitis B Third Dose Vaccine Coverage from 1980-2023 Across 204 Countries and Territories

Global Spatiotemporal Analysis in Hepatitis B Third Dose Vaccine Coverage from 1980-2023 Across 204 Countries and Territories | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Global Spatiotemporal Analysis in Hepatitis B Third Dose Vaccine Coverage from 1980-2023 Across 204 Countries and Territories Adewunmi Akingbola, Abiodun Adegbesan, Emmanuella Benson, Mmaduabuchi Ozioko, and 4 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9379366/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 6 You are reading this latest preprint version Abstract Introduction The Hepatitis B third dose (HepB3) vaccination is essential in preventing chronic infections, liver failure, and cancer. Despite progress, global coverage remains uneven, especially in low-income regions. This study analyzes the global and regional spatiotemporal trends in HepB3 vaccine coverage from 1980–2023 using the Global Burden of Disease (GBD) 2023 estimates. Methodology Data from GBD 2023, covering 204 countries and territories from 1980 to 2023, was analyzed to assess HepB3 vaccine coverage. Descriptive statistics summarized global and regional trends, and linear mixed-effects regression models evaluated the impact of time and region on coverage. The study also utilized choropleth maps to visualize global and regional coverage variations. Results Global coverage increased from near 0% in the 1980s to 81.82% in 2023. Regional disparities were evident, with Europe and Oceania showing higher coverage, while sub-Saharan Africa and South Asia lagged. Regression results indicated an annual increase in coverage of 2.50% (95% CI: 2.41%–2.59%, p < 0.0001). Albania had the highest global coverage at 98.2%, while Somalia had the lowest at 14%. Conclusion Global HepB3 coverage has significantly improved, but geographic disparities persist. Targeted interventions in low-coverage areas and strengthened healthcare systems are needed to meet the 2030 universal coverage goal. Hepatitis B third-dose vaccine spatiotemporal analysis global coverage regression model choropleth maps Figures Figure 1 Figure 2 Figure 3 1. INTRODUCTION Childhood immunisation has been recognised as one of the most successful and cost-effective public health interventions in history (1,2). Since the launch of the Expanded Programme on Immunisation by the World Health Organisation in 1974, immunisation has contributed to a significant reduction in morbidity and mortality due to vaccine-preventable diseases, hence the improvement in child survival and global life expectancy (1,3). Vaccines have been estimated to save millions of lives every year by preventing deaths, preventing long-term disability, and reducing healthcare costs related to infectious diseases (3). Apart from the direct benefits of vaccination, high coverage of vaccination ensures the principle of herd immunity, hence reducing the spread of the disease and protecting those who cannot be vaccinated (4,5). High routine immunisation coverage is therefore central to the achievement of global health priorities such as the Sustainable Development Goals and the Immunization Agenda 2030 (3). Among the routine vaccines, the hepatitis B vaccine is particularly important in the prevention of chronic viral infections and their long-term complications (6). Chronic hepatitis B virus infection is a significant global health problem, hence causing cirrhosis, liver failure, and hepatocellular carcinoma (6,7). The full hepatitis B vaccine series, culminating in the Hepatitis B third dose (HepB3), provides a high level of protection against chronic infection when given in infancy (6,8). High coverage of HepB3 is therefore important not only in the prevention of acute hepatitis B infection but also in the reduction of the long-term burden of liver cancer and liver-related deaths (9,10). HepB3 coverage is therefore often used as a proxy measure of the performance of the routine immunisation system and continuity of care in early childhood (9). Even though there has been significant progress over the last four decades, there has been a plateauing of vaccination coverage over the years, and there remain disparities in vaccination coverage between and within countries (1,11). According to WHO/UNICEF, the worldwide coverage of the third dose of hepatitis B vaccine has been below the target of ≥90%, which is recommended for disease elimination, with significant differences between regions (9,11). There is significantly lower coverage reported in several low- and middle-income regions, particularly in parts of sub-Saharan Africa and conflict-affected settings (9,11). Disruption of immunisation services due to weak health infrastructure, socioeconomic disparities, inaccessibility, political instability, vaccine hesitancy, and the COVID-19 pandemic has threatened the delivery of routine immunisation services (12,13). Global averages provide a good comparison; however, there is significant spatial heterogeneity and temporal variation in vaccination coverage across and within countries (14). The Global Burden of Disease Study 2023 (GBD 2023) provides a comprehensive platform for the analysis of global health trends, including vaccination coverage (15). It provides standardised and comparable estimates of childhood vaccination coverage in 204 countries from 1980 to 2023, using several data sources and advanced statistical modelling approaches (15,16). GBD provides a platform for the analysis of geographic and temporal variability in vaccine coverage across countries and over time (15). This is especially important for HepB3, because the reception of the third dose of the hepatitis B vaccine indicates sustained contact with the immunisation service during the first year of life (8). As such, the coverage of multiple-dose vaccines like the HepB3 is thought to be an indicator of the effectiveness of immunisation service delivery in nations (1). Therefore, this study aims to perform a global and regional spatiotemporal analysis of HepB3 vaccine coverage in 2023 based on the GBD 2023 estimates. The research goals are threefold: (i) to analyze the temporal trend of HepB3 coverage at the global and regional levels, (ii) to measure the geographic inequality of HepB3 coverage across 204 countries and territories and (iii) to examine the spatial and temporal variations that may be indicative of structural, socioeconomic and health system factors shaping the adoption of HepB3 vaccine. Through the combination of time and geographic perspectives, this study aims to produce evidence that can help develop strategies to improve immunisation systems, reduce inequities in vaccine access and accelerate the progress towards universal coverage of childhood vaccination. 2. METHODS Data Source The data used for this study was sourced from the Global Burden of Disease (GBD) Study 2023, provided by the Institute for Health Metrics and Evaluation (IHME) (17). The dataset includes estimates of vaccination coverage for 11 routine childhood vaccines, including the third-dose Hepatitis B (HepB3), from 1980 to 2023 across 204 countries and territories globally. This dataset provides coverage data on vaccines such as BCG, DTP, Polio, and MCV, among others. It is based on household survey microdata, which is further supplemented by the best available data when household surveys were unavailable. Additionally, the dataset estimates vaccination coverage under various scenarios and covers the full temporal span from 1980 to 2023, with forecasted estimates for 2024 to 2030. The data offers comprehensive insights into global vaccination trends, allowing for the examination of temporal and spatial changes in coverage for each vaccine. Statistical Analysis This study analyses the global trends in Hepatitis B third dose (HepB3) vaccine coverage using data from the Global Burden of Disease Study 2023 (GBD 2023). The dataset spans from 1980 to 2023, covering 204 countries and territories worldwide, and includes estimates of vaccination coverage for 11 childhood vaccines, including HepB3. The analysis first involved data preparation, where we cleaned and aggregated the dataset to categorize countries by continent and ensure accurate matching of countries and territories. Missing or inconsistent data were addressed, and the dataset was divided by regions to facilitate a meaningful comparison. We then computed descriptive statistics to provide insights into global and regional vaccination coverage. Mean, median, standard deviation, and interquartile range (IQR) were calculated for HepB3 coverage from 1980 to 2023, summarizing trends over the years. This helped to identify general patterns of vaccination adoption and measure the variability in coverage across countries and territories. The highest and lowest performing countries and continents were determined, providing a snapshot of where vaccine coverage has been most successful and where challenges remain. The data was visualized using global and regional choropleth maps, which helped to spatially represent coverage levels, and categorical maps were used to classify countries into low, moderate, and high vaccination coverage groups. To explore the temporal dynamics of vaccine coverage, we analysed the trends in HepB3 vaccination rates over the years, both globally and continent-wise, using line plots. These plots highlighted significant milestones in vaccination campaigns and demonstrated the progress made in different regions. Spatiotemporal trends were examined to assess how HepB3 coverage evolved in response to changing policies and vaccination strategies, with a particular focus on the period after the adoption of the vaccine. The study also employed linear mixed-effects regression models to assess the impact of time and region on vaccination coverage, accounting for both fixed and random effects. This statistical approach helped identify patterns and determine if certain factors, such as continent and year of vaccine introduction, were significant predictors of vaccination coverage. By combining statistical analysis with visualizations, this methodology provided a comprehensive understanding of global HepB3 vaccination trends and regional disparities, ultimately shedding light on both the successes and ongoing challenges in childhood vaccination programs. 3. RESULTS Global Analysis of HepB3 vaccine coverage Global descriptive statistics for HepB3 vaccine coverage from 1980 to 2023 demonstrate a marked transformation in the global distribution of third-dose hepatitis B vaccination across 204 countries and territories. In the early years (1980–1982), global coverage was negligible. The mean coverage was 0% in 1980 and 1981, and the median coverage was also 0%, indicating that at least half of all countries reported no measurable uptake. During this period, all 204 countries were classified within the low-coverage category (0–39%). Even by 1990, global mean coverage had increased only modestly to 8.19%, while the median remained at 0%, and over 90% of countries continued to fall within the low-coverage group. The minimum coverage during this period was consistently 0%, while maximum values gradually increased, reaching above 90% in a small number of countries. From the mid-1990s onward, substantial increases were observed. Between 1995 and 2000, the global mean coverage rose from 22.13% to 41.10%, and the median increased from 0% to 30.20%. By 2002, the median coverage had reached 71.75%, indicating that more than half of all countries had achieved coverage levels above 70%. Over the same interval, the proportion of countries in the high-coverage category (≥ 70%) increased markedly, rising from 21 countries in 1992 to 106 countries by 2002. Correspondingly, the number of countries in the low-coverage category declined substantially. The early 2000s marked a clear shift in global distribution. By 2005, the global mean coverage had reached 68.63%, with a median of 84.80%. At that time, 143 countries (70.1%) were classified as high coverage, while only 42 countries remained in the low-coverage category. This upward trajectory continued through the late 2000s. By 2010, the mean coverage was 78.14%, and the median was 88.85%, with 158 countries (77.5%) in the high-coverage category and only 17 countries in the low category. From 2011 onward, global coverage levels remained relatively stable. Between 2011 and 2023, the mean coverage fluctuated within a narrow range, from approximately 78.6% to 82.1%. The median coverage consistently remained high, ranging between 87% and 89.5%. By 2023, the global mean coverage was 81.82%, and the median was 87.43%. In that year, 171 countries (83.8%) were classified as high coverage, 26 countries (12.7%) as moderate coverage, and 7 countries (3.4%) as low coverage. Measures of dispersion also evolved over time. The interquartile range (IQR) was 0 in the early 1980s, reflecting uniformly low coverage. It expanded substantially during the late 1990s and early 2000s, reaching values above 80 percentage points, before narrowing again in the 2010s to approximately 18–20 percentage points. The standard deviation followed a similar pattern, peaking during the rapid expansion phase and declining thereafter. Across all years combined following vaccine adoption, Albania (Europe) recorded the highest overall HepB3 coverage globally, with a mean coverage of 98.2% over 30 years post-adoption. In contrast, Somalia (Africa) had the lowest overall post-adoption coverage, with a mean of 14.0% across 11 years. Additionally, four countries, Denmark, Finland, Hungary, and Iceland recorded 0% coverage throughout the study period, indicating that they did not adopt the HepB3 vaccine within the timeframe captured by the dataset. The global HepB3 vaccine coverage trends from 1980 to 2023 are corroborated by the choropleth maps in Figs. 1 and 2 , which visually highlight the substantial progress in vaccination coverage over the years, and by the linear mixed-effects regression model which showed that HepB3 vaccination coverage increased by an average of 2.50% per year from 1980 to 2023 (95% CI: 2.41%–2.59%). This annual increase was found to be statistically significant (p < 0.0001). In 1980, the map clearly shows that most countries had negligible coverage, with the majority of regions marked in dark shades, indicating a lack of vaccine access or administration. Fast forward to 2023, and the map reflects the improvements, with the majority of countries now categorized under high coverage (≥ 70%), particularly in Europe, Oceania, and parts of Asia. However, regions such as sub-Saharan Africa and some parts of South Asia still show lower coverage rates, as represented in the map by the green and blue areas for low and moderate coverage, respectively. These visualizations align with the statistical results, confirming the widespread progress, while also highlighting ongoing gaps in coverage across specific geographic regions. Continent-level Analysis The continent-level descriptive analysis of HepB3 vaccination coverage from 1980 to 2023 demonstrates pronounced differences in both the timing and magnitude of coverage expansion across world regions. In 1980, all continents recorded an average and median coverage of 0%, reflecting the absence of HepB3 uptake globally at that time. This pattern persisted across regions through much of the 1980s. By 2000, substantial divergence had emerged. As seen in Table 1 , Oceania reported the highest average coverage at 75.6%, with a median of 84.6%, while Asia and Europe recorded moderate average coverage levels of 50.4% and 48.6%, respectively. In contrast, Africa and South America lagged, with average coverages of 15.9% and 29.8%, and median values of 0% and 8.4%, respectively. During this period, within-continent variability was high, particularly in Asia and Europe, where standard deviations exceeded 40 percentage points. By 2010, all continents had achieved marked increases in coverage. South America reported the highest average coverage at 88.0%, followed by Asia at 83.4%, North America at 80.4%, and Oceania at 80.2%. Europe and Africa recorded average coverages of 75.4% and 72.0%, respectively. Median coverage exceeded 76% in all continents, with Asia and Europe reporting medians above 90%. Variability declined in most regions, particularly in South America, where the standard deviation fell to 5.6%. In 2023, high coverage levels were sustained across all continents. Asia recorded the highest average coverage at 86.7% (median: 92.5%), followed by Europe at 82.6% (median: 91.9%) and South America at 81.6% (median: 81.8%). Oceania and North America reported similar average coverages of 80.9% and 81.0%, respectively, while Africa recorded the lowest average coverage at 76.5%, despite a median of 82.0%. The average HepB3 vaccination coverage trends from 1980 to 2023 across continents in Fig. 3 shows a clear upward trajectory for all regions, with significant increases over time. Africa, Asia, Europe, and North America exhibit a steady rise in coverage, with most continents reaching around 80% coverage in recent years. Oceania shows a similar increase, although with some fluctuations. South America follows a similar pattern, reaching a high percentage of coverage in the last two decades. Overall, dispersion continued to narrow across continents, indicating reduced within-region variability by the end of the study period. Table 1 Highest and Lowest Performing Countries by Continent Continent Highest Performing Country Years After Adoption Mean Coverage (%) Lowest Performing Country Years After Adoption Mean Coverage (%) Africa Seychelles 29 96.7 Somalia 11 14.0 Asia Turkmenistan 22 97.1 Afghanistan 18 50.1 Europe Albania 30 98.2 Switzerland 11 51.2 North America Nicaragua 25 96.3 Canada 26 41.3 South America Uruguay 25 92.3 Venezuela (Bolivarian Republic of) 24 66.2 Oceania Tonga 36 97.4 Papua New Guinea 35 42.1 4. DISCUSSION This study presents findings from the spatiotemporal analysis of HepB3 vaccination coverage across 204 countries and territories from 1980 to 2023. Vaccination rates have increased markedly over the decades, painting an overall positive picture. The ascent from near-zero global mean coverage in 1980 to 81.82% by 2023, with a statistically significant annual increase of 2.50% (95% CI: 2.41%–2.59%, p < 0.0001), represents one of the most remarkable achievements in modern public health. Yet, the progress hasn't been equal. The fact that 33 countries were still classified in the low-to-moderate coverage groups in 2023 shows that much work remains to be done, and that overall optimism should not hide the differences between countries. Some regions and countries have consistently lagged behind, and those gaps are tied to geography, meaning where a child is born still heavily influences whether they get vaccinated. The near-zero coverage recorded globally through the early 1980s is consistent with the pre-commercial availability of recombinant hepatitis B vaccines, which only became widely accessible from 1986 onward. The pronounced acceleration observed from the mid-1990s into the early 2000s coincides directly with the establishment of the Global Alliance for Vaccines and Immunization (GAVI) in 2000 and the subsequent mass rollout of the pentavalent combination vaccine in low-income countries. Reductions in vaccine costs and sustained financial and logistical support from Gavi since the early 2000s contributed significantly to expanding vaccine coverage in many low-income countries ( 18 ). The median coverage exceeded 70% by 2002, indicating that more than half of countries had achieved high coverage, supported this interpretation and highlighted the role of international financing mechanisms in accelerating vaccine adoption ( 18 ). The stabilization of global coverage after 2011, with the mean remaining between 78.6% and 82.1% in the final decade of the study; is both notable and concerning. This suggests that while the early gains from vaccine introduction and global financing have largely been sustained, further progress has been difficult to achieve. This stagnation is not unexpected. Many countries still below the WHO ≥ 90% elimination target struggle with uneven vaccine coverage, low completion of the three-dose series, and challenges in conflict-affected or poorly resourced areas ( 19 ). The interquartile range shrank from over 80 percentage points in the late 1990s to around 18–20 points by the 2010s, showing that coverage levels are becoming more similar worldwide. However, this progress is uneven, with many countries either reaching high coverage or remaining far below the ≥ 90% target. At the continental level, gaps in HepB3 coverage remain substantial and carry significant epidemiological implications. Africa’s persistently lower coverage, with a continental average of 76.5% in 2023 compared to Asia’s 86.7%, should be considered in the context of the continent’s disproportionately high burden of hepatitis B infection. Geographic analyses of African HepB3 coverage have documented that continental coverage rose only marginally from 68.06% in 2010 to 69.42% in 2022, with critically low coverage below 40% persisting across the Sahel, the Democratic Republic of the Congo, Angola, and northern Mozambique ( 19 ). Of the 51 African countries assessed, only six; Rwanda, Eritrea, Eswatini, Burkina Faso, Zimbabwe, and Niger were projected to be on track to meet the 90% coverage target by 2030. This is a sobering indictment of the systemic barriers to vaccine delivery across much of the continent, including inadequate cold chain infrastructure, high rates of out-of-facility births, limited numbers of skilled birth attendants in rural and remote areas, and the logistical challenges inherent in administering vaccines at birth ( 20 – 22 ). The country-level extremes identified in this study are revealing. Albania had the highest mean coverage globally, reaching 98.2% over 30 years after adopting the vaccine. This success reflects the effectiveness of a well-funded, centralized national immunization program within a functioning healthcare system that benefits from strong political support for childhood vaccination. By contrast, Somalia’s average coverage of 14.0% over 11 years reflects the combined effects of prolonged armed conflict, the near-complete breakdown of public health infrastructure, and persistent poverty. Studies of hepatitis B vaccination in Somalia have shown that key barriers to uptake include frequent vaccine unavailability, the high cost of vaccination, and limited awareness of the disease and the benefits of vaccination among at-risk groups ( 23 ). HepB3 was introduced late into Somalia’s national routine immunization program, only in 2013 through the pentavalent vaccine. This explains the short post-adoption period reflected in the dataset. Canada's low mean of 41.3% over 26 years presents a different, and perhaps more counterintuitive, case: several high-income European and North American countries, including Denmark, Finland, Hungary, and Iceland, recorded 0% coverage for the entire study period, reflecting deliberate national policy decisions not to adopt universal HepB3 vaccination given their low endemic disease burden. This heterogeneity among high-income countries illustrates that coverage gaps are not exclusively a function of resource constraints; they are also shaped by epidemiological risk perception and public health policy priorities. The COVID-19 pandemic caused a major external disruption to routine immunization services, which should be considered when interpreting HepB3 coverage trends from 2020 onward. WHO and UNICEF data confirmed that 23 million children missed basic vaccines through routine immunisation services in 2020 alone, 3.7 million more than in 2019, with the majority residing in conflict-affected, remote, or informally settled communities ( 24 , 25 ). The global routine vaccine doses fell by approximately 30% in April 2020 relative to expected levels, representing the most widespread disruption to immunisation services in recent history ( 12 ). Research drawing on WHO/UNICEF coverage data showed that vaccine coverage was significantly below predicted levels for 13 of 16 antigens in 2020 and for all assessed antigens in 2021, with the most pronounced shortfalls in South America, Africa, Eastern Europe, and Southeast Asia ( 26 ). HepB3 coverage remained relatively stable between 2011 and 2023, with only a slight decline in its narrow range. This stability may partly mask disruptions caused by the pandemic, which could become clearer as longer-term data become available. The WHO’s 2030 target of ≥ 90% HepB3 coverage for all member states is theoretically attainable but achieving it will require a change in strategy rather than simply intensifying current efforts. Regional disparities in WHO coverage estimates are substantial, with the Western Pacific region achieved relatively high third-dose hepatitis B (HepB3) coverage, while the Americas and Southeast Asia approaching similar levels, while Africa and the Eastern Mediterranean remain significantly below the global average ( 27 ). To close existing gaps in hepatitis B prevention, several key actions are required. First, there must be prioritized investment in strengthening health systems within fragile and low-income areas ( 22 ). ​A critical step is the accelerated introduction of the hepatitis B birth-dose vaccine across Africa. This is a major priority because, by 2022, only 15 out of 47 member states in the region had adopted universal birth-dose programs ( 22 ). Additionally, there is a need for targeted interventions in specific districts where vaccination rates remain low despite improvements at the national level. These local gaps are often caused by barriers such as high rates of home births and the logistical difficulty of delivering the vaccine shortly after birth ( 22 , 28 ). The linear mixed-effects regression results from this study, which identified statistically significant regional and temporal factors influencing HepB3 coverage, support the idea that geography and the policy environment are key, rather than incidental, determinants of vaccination outcomes. In summary, global HepB3 vaccination has seen remarkable progress, yet persistent inequities remain. Over the past four decades, many regions have reached near-universal coverage thanks to coordinated investments and strong political commitment ( 22 ). Despite these achievements, significant gaps continue to exist, especially in Africa, where average coverage is only 76.5%. Inequities are also visible within higher-income regions; for example, Nicaragua reports 96.3% coverage, while Canada lags at 41.3%. Addressing these disparities will require targeted subnational interventions and faster adoption of hepatitis B birth-dose vaccines to ensure that no community is left behind ( 28 ). 5. RECOMMENDATIONS AND CONCLUSION Drawing on the findings of our study, and the broader body of evidence on childhood immunization performance, several policy and programmatic priorities emerge for sustaining progress and addressing the persistent disparities observed in HepB3 vaccine coverage. While global trends demonstrate substantial improvements over the past four decades, targeted and coordinated strategies will be necessary to ensure that these gains translate into equitable protection for children in all regions. Our recommendations are as follows: Strengthen National Immunization Policies and Routine Vaccine Delivery Systems: Governments should continue to prioritize strong national immunization policies that support consistent delivery of routine childhood vaccines, including the hepatitis B third dose. Policy commitments should be matched with adequate financing for immunization programs, improved cold-chain infrastructure, and sustained investment in healthcare workforce capacity (29). Strengthening supply chain management and service delivery platforms will be essential to maintaining high coverage and preventing disruptions in vaccine availability (30). Prioritize Targeted Interventions in Low-Coverage and Fragile Settings: In the wake of reducing donor-based healthcare spending, it is important that countries and regions with persistently low HepB3 coverage develop context-specific interventions designed to reach populations that remain underserved by routine immunization services. Outreach vaccination campaigns, mobile clinics, and partnerships with local community organizations can play an important role in expanding vaccine access (31). Such approaches are particularly critical in fragile and conflict-affected settings where health system capacity may be limited and help ensure adequate resource utilization. Integrate Hepatitis B Vaccination with Maternal and Child Health Services: Integrating hepatitis B vaccination within broader maternal and child health programs can improve early entry into immunization schedules and increase completion of the recommended vaccine series. Linking vaccination services with antenatal care, delivery services, and postnatal follow-up can strengthen continuity of care and enhance vaccine uptake (32). Particular emphasis should also be placed on improving timely birth-dose administration, especially in settings where facility-based deliveries remain limited. Promote Community Engagement and Strengthen Vaccine Confidence: Sustained improvements in vaccination coverage require strong community trust in immunization programs. Governments and public health institutions should implement culturally appropriate communication strategies that address misinformation, improve public awareness of the benefits of vaccination, and encourage adherence to recommended immunization schedules (33). Engagement with community leaders, healthcare providers, and civil society organizations can further support these efforts. Strengthen Surveillance Systems and Data-Driven Decision Making: Robust data systems remain fundamental to effective immunization policy and program planning. Strengthening national health information systems will enable more accurate monitoring of vaccination coverage and facilitate early identification of underserved populations (34). Continued investment in global monitoring frameworks, including the Global Burden of Disease (GBD) estimates and WHO-UNICEF Estimates of National Immunization Coverage (WUENIC), will be essential for tracking progress and informing evidence-based policy responses. Sustain Global Collaboration and Financing for Immunization Programs: Continued international collaboration will remain critical for supporting countries with limited resources in strengthening their immunization systems. Partnerships involving governments, multilateral organizations, and global health initiatives can provide financial support, technical expertise, and capacity-building opportunities (35). Strengthening these collaborative efforts will be key to reducing inequities in vaccine access and advancing progress toward global immunization targets. CONCLUSION As captured by our findings, this study highlights both the remarkable progress achieved in global hepatitis B immunization and the persistent geographic disparities that continue to influence vaccine coverage.In the early years of the study period, HepB3 vaccination coverage was minimal, reflecting the limited availability of hepatitis B vaccines and the absence of widespread immunization policies. The global adoption of universal childhood hepatitis B vaccination strategies in the mid-1990s marked a pivotal turning point, driving a rapid expansion in vaccine uptake over the following decade. By 2023, global mean HepB3 coverage had reached approximately 81.8%, with the majority of countries achieving high levels of vaccination coverage. This trajectory reflects the collective impact of sustained immunization initiatives, national policy commitments, and international partnerships dedicated to expanding vaccine access. At the same time, the persistence of lower coverage in parts of sub-Saharan Africa and South Asia underscores the enduring influence of health system constraints, socioeconomic disparities, and logistical barriers to vaccine delivery. The global progress observed over the past four decades represents a significant achievement in preventive public health. However, the remaining gaps in coverage make clear that progress has not been evenly distributed. Closing these gaps will require renewed investments in immunization systems, stronger policy implementation, and targeted strategies that prioritize underserved populations. Ultimately, achieving equitable HepB3 coverage is both an attainable goal and an urgent public health imperative. Sustained commitment from national governments, global health institutions, and development partners will be essential to ensure that every child, regardless of geography or circumstance, benefits from the life-saving protection afforded by hepatitis B vaccination. Declarations ETHICS APPROVAL AND CONSENT TO PARTICIPATE. Not Applicable ACKNOWLEDGEMENTS. Not Applicable CONSENT FOR PUBLICATION Not Applicable FUNDING STATEMENT. No funding was obtained for this research project. DECLARATION OF INTERESTS All authors declare no competing interest. CLINICAL TRIAL NUMBER Not applicable DATA AVAILABILITY STATEMENT We used data from the Global Burden of Disease Study 2023, and can be found below. Institute for Health Metrics and Evaluation (IHME). Global Burden of Disease Study 2023 (GBD 2023) Routine Childhood Vaccination Coverage Estimates and Forecasts 1980-2030. Seattle, United States of America: Institute for Health Metrics and Evaluation (IHME), 2025. https://doi.org/10.6069/JCH3-FT68 AUTHORS CONTRIBUTION STATEMENT Adewunmi Akingbola conceptualized the study, did the data analysis and wrote the methodology, results and abstracts, Olajumoke Adewole, Maxwell Boakye, Abiodun Adegbesan, Petra Mariaria edited the manuscript, Emmanuella Benson wrote the Discussion, Ozioko wrote the Introduction, Khalil-ur-Rahman wrote the Recommendations and Conclusion. All authors have agreed to this manuscript. References Immunization coverage [Internet]. [cited 2026 Mar 9]. Available from: https://www.who.int/news-room/fact-sheets/detail/immunization-coverage Return On Investment From Childhood Immunization In Low- And Middle-Income Countries, 2011–20 | Health Affairs [Internet]. [cited 2026 Mar 9]. Available from: https://www.healthaffairs.org/doi/10.1377/hlthaff.2015.1086 Immunization Agenda 2030 [Internet]. [cited 2026 Mar 9]. Available from: https://www.who.int/teams/immunization-vaccines-and-biologicals/strategies/ia2030 “Herd Immunity”: A Rough Guide | Clinical Infectious Diseases | Oxford Academic [Internet]. [cited 2026 Mar 9]. Available from: https://academic.oup.com/cid/article/52/7/911/299077 Bullen M, Heriot GS, Jamrozik E. Herd immunity, vaccination and moral obligation. J Med Ethics. 2023 Sep;49(9):636–41. doi:10.1136/jme-2022-108485 PubMed PMID: 37277175; PubMed Central PMCID: PMC10511978. Hepatitis B vaccines: WHO position paper – July 2017 [Internet]. [cited 2026 Mar 9]. Available from: https://www.who.int/publications/i/item/WER9227 Polaris Observatory Collaborators. Global prevalence, treatment, and prevention of hepatitis B virus infection in 2016: a modelling study. Lancet Gastroenterol Hepatol. 2018 Jun;3(6):383–403. doi:10.1016/S2468-1253(18)30056-6 PubMed PMID: 29599078. Schillie S, Vellozzi C, Reingold A, Harris A, Haber P, Ward JW, et al. Prevention of Hepatitis B Virus Infection in the United States: Recommendations of the Advisory Committee on Immunization Practices. MMWR Recomm Rep. 2018 Jan 12;67(1):1–31. doi:10.15585/mmwr.rr6701a1 PubMed PMID: 29939980; PubMed Central PMCID: PMC5837403. Immunization Data [Internet]. [cited 2026 Mar 9]. WHO Immunization Data portal - Global. Available from: https://immunizationdata.who.int Flores JE, Thompson AJ, Ryan M, Howell J. The Global Impact of Hepatitis B Vaccination on Hepatocellular Carcinoma. Vaccines. 2022 May 17;10(5). doi:10.3390/vaccines10050793 Global progress report on HIV, viral hepatitis and sexually transmitted infections, 2021 [Internet]. [cited 2026 Mar 9]. Available from: https://www.who.int/publications/i/item/9789240027077 Causey K, Fullman N, Sorensen RJD, Galles NC, Zheng P, Aravkin A, et al. Estimating global and regional disruptions to routine childhood vaccine coverage during the COVID-19 pandemic in 2020: a modelling study. The Lancet. 2021 Aug 7;398(10299):522–34. doi:10.1016/S0140-6736(21)01337-4 Ali HA, Hartner AM, Echeverria-Londono S, Roth J, Li X, Abbas K, et al. Vaccine equity in low and middle income countries: a systematic review and meta-analysis. Int J Equity Health. 2022 Jun 11;21:82. doi:10.1186/s12939-022-01678-5 PubMed PMID: 35701823; PubMed Central PMCID: PMC9194352. Spatial clustering of measles vaccination coverage among children in sub-Saharan Africa | BMC Public Health | Springer Nature Link [Internet]. [cited 2026 Mar 9]. Available from: https://link.springer.com/article/10.1186/s12889-017-4961-9 Global Burden of Disease (GBD) [Internet]. [cited 2026 Mar 9]. Available from: https://www.healthdata.org/research-analysis/gbd Vos T, Lim SS, Abbafati C, Abbas KM, Abbasi M, Abbasifard M, et al. Global burden of 369 diseases and injuries in 204 countries and territories, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019. The Lancet. 2020 Oct 17;396(10258):1204–22. doi:10.1016/S0140-6736(20)30925-9 Institute for Health Metrics and Evaluation. Global Burden of Disease Study 2023 (GBD 2023) Routine Childhood Vaccination Coverage Estimates and Forecasts 1980-2030 [Internet]. Institute for Health Metrics and Evaluation; 2025 [cited 2026 Mar 9]. Available from: https://ghdx.healthdata.org/record/ihme-data/gbd-2023-vaccination-coverage-1980-2030 doi:10.6069/JCH3-FT68 Al-Busafi SA, Alwassief A. Global Perspectives on the Hepatitis B Vaccination: Challenges, Achievements, and the Road to Elimination by 2030. Vaccines. 2024 Mar 9;12(3). doi:10.3390/vaccines12030288 Yu J, Chen X, Li H, Xu Z, Liu Y, Zhang X, et al. Geographic disparities in hepatitis B vaccine coverage across Africa: Implications for targeted interventions and 2030 goals. Journal of Hepatology. 2025 Nov 24. doi:10.1016/j.jhep.2025.11.016 Barriers to childhood immunization in sub-Saharan Africa: A systematic review | BMC Public Health | Springer Nature Link [Internet]. [cited 2026 Mar 9]. Available from: https://link.springer.com/article/10.1186/s12889-020-09169-4 Solomon-Rakiep T, Olivier J, Amponsah-Dacosta E. Weak Adoption and Performance of Hepatitis B Birth-Dose Vaccination Programs in Africa: Time to Consider Systems Complexity?-A Scoping Review. Trop Med Infect Dis. 2023 Oct 16;8(10):474. doi:10.3390/tropicalmed8100474 PubMed PMID: 37888602; PubMed Central PMCID: PMC10611266. Frontiers | Towards contextualized complex systems approaches to scaling-up hepatitis B birth-dose vaccination in the African region: a qualitative systematic review [Internet]. [cited 2026 Mar 9]. Available from: https://www.frontiersin.org/journals/public-health/articles/10.3389/fpubh.2024.1389633/full –Tuuryare SAH, Timothy KK, Mohamud MH. Hepatitis B vaccination coverage and associated factors among adults in Somalia: a cross-sectional study. BMC Public Health. 2025 Nov 12;25(1):3917. doi:10.1186/s12889-025-25171-0 COVID-19 pandemic leads to major backsliding on childhood vaccinations, new WHO, UNICEF data shows [Internet]. [cited 2026 Mar 9]. Available from: https://www.unicef.org/press-releases/covid-19-pandemic-leads-major-backsliding-childhood-vaccinations-new-who-unicef-data COVID-19 pandemic fuels largest continued backslide in vaccinations in three decades [Internet]. [cited 2026 Mar 9]. Available from: https://www.who.int/news/item/15-07-2022-covid-19-pandemic-fuels-largest-continued-backslide-in-vaccinations-in-three-decades Ghaznavi C, Eguchi A, Suu Lwin K, Yoneoka D, Tanoue Y, Kumar Rauniyar S, et al. Estimating global changes in routine childhood vaccination coverage during the COVID-19 pandemic, 2020–2021. Vaccine. 2023 Jun 23;41(28):4151–7. doi:10.1016/j.vaccine.2023.05.034 CGHE [Internet]. [cited 2026 Mar 9]. Introduction of Hepatitis B Birth Dose Vaccination in Africa: A Toolkit for National Immunization Technical Advisory Groups. Available from: https://www.globalhep.org/tools-resources/introduction-hepatitis-b-birth-dose-vaccination-africa-toolkit-national Boisson A, Goel V, Yotebieng M, Parr JB, Fried B, Thompson P. Implementation Approaches for Introducing and Overcoming Barriers to Hepatitis B Birth-Dose Vaccine in sub-Saharan Africa. Global Health: Science and Practice. 2022 Feb 28;10(1). doi:10.9745/GHSP-D-21-00277 PubMed PMID: 35294378. Oyugi B, Kallander K, Shahabuddin ASM. Strengthening Primary Health Care Through Implementation Research: Strategies for Reaching Zero-Dose Children in Low- and Middle-Income Countries’ Immunization Programs. Vaccines (Basel). 2025 Oct 9;13(10):1040. doi:10.3390/vaccines13101040 PubMed PMID: 41150428; PubMed Central PMCID: PMC12568197. Medicine NA of, National Academies of Sciences E, Division H and M, Health B on G, Response C on AI of VD and SC to AP and SIP and, Ashby E, et al. Vaccine Distribution and Delivery. In: Globally Resilient Supply Chains for Seasonal and Pandemic Influenza Vaccines [Internet]. National Academies Press (US); 2021 [cited 2026 Mar 9]. Available from: https://www.ncbi.nlm.nih.gov/books/NBK580009/ Pennisi F, Genovese C, Gianfredi V. Lessons from the COVID-19 Pandemic: Promoting Vaccination and Public Health Resilience, a Narrative Review. Vaccines (Basel). 2024 Aug 7;12(8):891. doi:10.3390/vaccines12080891 PubMed PMID: 39204017; PubMed Central PMCID: PMC11359644. Wilcox CR, Woodward C, Rowe R, Jones CE. Embedding the delivery of antenatal vaccination within routine antenatal care: a key opportunity to improve uptake. Hum Vaccin Immunother. 2019 Jul 24;16(5):1221–4. doi:10.1080/21645515.2019.1640558 PubMed PMID: 31339429; PubMed Central PMCID: PMC7227681. Dickson K, Aboltins C, Pelly J, Jessup RL. Effective communication of COVID-19 vaccine information to recently-arrived culturally and linguistically diverse communities from the perspective of community engagement and partnership organisations: a qualitative study. BMC Health Serv Res. 2023 Aug 21;23:877. doi:10.1186/s12913-023-09836-3 PubMed PMID: 37605184; PubMed Central PMCID: PMC10440864. Stockwell MS, Fiks AG. Utilizing health information technology to improve vaccine communication and coverage. Hum Vaccin Immunother. 2013 Aug 1;9(8):1802–11. doi:10.4161/hv.25031 PubMed PMID: 23807361; PubMed Central PMCID: PMC3906285. Arabi S, Butler-Henderson K, Jones S, Vindigni D. Enhancing collaborative international partnerships in healthcare – a systematic review of insights, challenges, and pathways to sustainability. Social Sciences & Humanities Open. 2025 Jan 1;12:101914. doi:10.1016/j.ssaho.2025.101914 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Reviewers agreed at journal 16 May, 2026 Reviewers invited by journal 07 May, 2026 Editor invited by journal 19 Apr, 2026 Editor assigned by journal 13 Apr, 2026 Submission checks completed at journal 13 Apr, 2026 First submitted to journal 10 Apr, 2026 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. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. 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-9379366","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":625912864,"identity":"6a264de8-d9a6-434c-b2ab-186fa11be47f","order_by":0,"name":"Adewunmi Akingbola","email":"","orcid":"","institution":"New York University Langone Health, United States of America","correspondingAuthor":false,"prefix":"","firstName":"Adewunmi","middleName":"","lastName":"Akingbola","suffix":""},{"id":625912868,"identity":"0de2852b-e8e6-4324-b48f-f50fb7febd46","order_by":1,"name":"Abiodun Adegbesan","email":"","orcid":"","institution":"University of 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12:11:04","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-9379366/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9379366/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":107489719,"identity":"3ef265d6-5809-4b44-85cf-6c2968cf4b3a","added_by":"auto","created_at":"2026-04-22 02:48:48","extension":"jpeg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":131371,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eGlobal Hepatitis B coverage (third dose) in 1980 and 2023\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"floatimage1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-9379366/v1/b9ee1f4a095bb1b67c749a32.jpeg"},{"id":107489807,"identity":"066346c4-54de-4667-ad37-98de28ec8311","added_by":"auto","created_at":"2026-04-22 02:49:02","extension":"jpeg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":116685,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eGlobal Hepatitis B coverage (third dose) by High, Moderate and Low categories in 1980 and 2023\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"floatimage2.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-9379366/v1/291d005280bd4857ea557bec.jpeg"},{"id":107489796,"identity":"fd241d6f-2dd7-4b1d-8e49-7c128595d22d","added_by":"auto","created_at":"2026-04-22 02:49:00","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":169790,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eGlobal trend of Hepatitis B coverage (third dose) by continent\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"floatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-9379366/v1/7fdf01e3467488b4f2a61ade.png"},{"id":107490177,"identity":"2cdbe13a-d8b4-4636-823d-bd96624bbb8c","added_by":"auto","created_at":"2026-04-22 02:51:03","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":871959,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9379366/v1/c3b19e7b-f7e6-4193-b409-efe2a4d91a89.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Global Spatiotemporal Analysis in Hepatitis B Third Dose Vaccine Coverage from 1980-2023 Across 204 Countries and Territories","fulltext":[{"header":"1.\tINTRODUCTION ","content":"\u003cp\u003eChildhood immunisation has been recognised as one of the most successful and cost-effective public health interventions in history (1,2). Since the launch of the Expanded Programme on Immunisation by the World Health Organisation in 1974, immunisation has contributed to a significant reduction in morbidity and mortality due to vaccine-preventable diseases, hence the improvement in child survival and global life expectancy (1,3). Vaccines have been estimated to save millions of lives every year by preventing deaths, preventing long-term disability, and reducing healthcare costs related to infectious diseases (3). Apart from the direct benefits of vaccination, high coverage of vaccination ensures the principle of herd immunity, hence reducing the spread of the disease and protecting those who cannot be vaccinated (4,5). High routine immunisation coverage is therefore central to the achievement of global health priorities such as the Sustainable Development Goals and the Immunization Agenda 2030 (3).\u003c/p\u003e\n\u003cp\u003eAmong the routine vaccines, the hepatitis B vaccine is particularly important in the prevention of chronic viral infections and their long-term complications (6). Chronic hepatitis B virus infection is a significant global health problem, hence causing cirrhosis, liver failure, and hepatocellular carcinoma (6,7). The full hepatitis B vaccine series, culminating in the Hepatitis B third dose (HepB3), provides a high level of protection against chronic infection when given in infancy (6,8). High coverage of HepB3 is therefore important not only in the prevention of acute hepatitis B infection but also in the reduction of the long-term burden of liver cancer and liver-related deaths (9,10). HepB3 coverage is therefore often used as a proxy measure of the performance of the routine immunisation system and continuity of care in early childhood (9).\u003c/p\u003e\n\u003cp\u003eEven though there has been significant progress over the last four decades, there has been a plateauing of vaccination coverage over the years, and there remain disparities in vaccination coverage between and within countries (1,11). According to WHO/UNICEF, the worldwide coverage of the third dose of hepatitis B vaccine has been below the target of \u0026ge;90%, which is recommended for disease elimination, with significant differences between regions (9,11). There is significantly lower coverage reported in several low- and middle-income regions, particularly in parts of sub-Saharan Africa and conflict-affected settings (9,11). Disruption of immunisation services due to weak health infrastructure, socioeconomic disparities, inaccessibility, political instability, vaccine hesitancy, and the COVID-19 pandemic has threatened the delivery of routine immunisation services (12,13). Global averages provide a good comparison; however, there is significant spatial heterogeneity and temporal variation in vaccination coverage across and within countries (14).\u003c/p\u003e\n\u003cp\u003eThe Global Burden of Disease Study 2023 (GBD 2023) provides a comprehensive platform for the analysis of global health trends, including vaccination coverage (15). It provides standardised and comparable estimates of childhood vaccination coverage in 204 countries from 1980 to 2023, using several data sources and advanced statistical modelling approaches (15,16). GBD provides a platform for the analysis of geographic and temporal variability in vaccine coverage across countries and over time (15). This is especially important for HepB3, because the reception of the third dose of the hepatitis B vaccine indicates sustained contact with the immunisation service during the first year of life (8). As such, the coverage of multiple-dose vaccines like the HepB3 is thought to be an indicator of the effectiveness of immunisation service delivery in nations (1).\u003c/p\u003e\n\u003cp\u003eTherefore, this study aims to perform a global and regional spatiotemporal analysis of HepB3 vaccine coverage in 2023 based on the GBD 2023 estimates. The research goals are threefold: (i) to analyze the temporal trend of HepB3 coverage at the global and regional levels, (ii) to measure the geographic inequality of HepB3 coverage across 204 countries and territories and (iii) to examine the spatial and temporal variations that may be indicative of structural, socioeconomic and health system factors shaping the adoption of HepB3 vaccine. Through the combination of time and geographic perspectives, this study aims to produce evidence that can help develop strategies to improve immunisation systems, reduce inequities in vaccine access and accelerate the progress towards universal coverage of childhood vaccination.\u003c/p\u003e"},{"header":"2.\tMETHODS","content":"\u003cp\u003e\u003cstrong\u003eData Source\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe data used for this study was sourced from the Global Burden of Disease (GBD) Study 2023, provided by the Institute for Health Metrics and Evaluation (IHME) (17). The dataset includes estimates of vaccination coverage for 11 routine childhood vaccines, including the third-dose Hepatitis B (HepB3), from 1980 to 2023 across 204 countries and territories globally. This dataset provides coverage data on vaccines such as BCG, DTP, Polio, and MCV, among others. It is based on household survey microdata, which is further supplemented by the best available data when household surveys were unavailable. Additionally, the dataset estimates vaccination coverage under various scenarios and covers the full temporal span from 1980 to 2023, with forecasted estimates for 2024 to 2030. The data offers comprehensive insights into global vaccination trends, allowing for the examination of temporal and spatial changes in coverage for each vaccine.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStatistical Analysis\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study analyses the global trends in Hepatitis B third dose (HepB3) vaccine coverage using data from the Global Burden of Disease Study 2023 (GBD 2023). The dataset spans from 1980 to 2023, covering 204 countries and territories worldwide, and includes estimates of vaccination coverage for 11 childhood vaccines, including HepB3. The analysis first involved data preparation, where we cleaned and aggregated the dataset to categorize countries by continent and ensure accurate matching of countries and territories. Missing or inconsistent data were addressed, and the dataset was divided by regions to facilitate a meaningful comparison.\u003c/p\u003e\n\u003cp\u003eWe then computed descriptive statistics to provide insights into global and regional vaccination coverage. Mean, median, standard deviation, and interquartile range (IQR) were calculated for HepB3 coverage from 1980 to 2023, summarizing trends over the years. This helped to identify general patterns of vaccination adoption and measure the variability in coverage across countries and territories. The highest and lowest performing countries and continents were determined, providing a snapshot of where vaccine coverage has been most successful and where challenges remain. The data was visualized using global and regional choropleth maps, which helped to spatially represent coverage levels, and categorical maps were used to classify countries into low, moderate, and high vaccination coverage groups.\u003c/p\u003e\n\u003cp\u003eTo explore the temporal dynamics of vaccine coverage, we analysed the trends in HepB3 vaccination rates over the years, both globally and continent-wise, using line plots. These plots highlighted significant milestones in vaccination campaigns and demonstrated the progress made in different regions. Spatiotemporal trends were examined to assess how HepB3 coverage evolved in response to changing policies and vaccination strategies, with a particular focus on the period after the adoption of the vaccine.\u003c/p\u003e\n\u003cp\u003eThe study also employed linear mixed-effects regression models to assess the impact of time and region on vaccination coverage, accounting for both fixed and random effects. This statistical approach helped identify patterns and determine if certain factors, such as continent and year of vaccine introduction, were significant predictors of vaccination coverage. By combining statistical analysis with visualizations, this methodology provided a comprehensive understanding of global HepB3 vaccination trends and regional disparities, ultimately shedding light on both the successes and ongoing challenges in childhood vaccination programs.\u003c/p\u003e"},{"header":"3. RESULTS","content":"\u003cdiv id=\"Sec2\" class=\"Section2\"\u003e \u003ch2\u003eGlobal Analysis of HepB3 vaccine coverage\u003c/h2\u003e \u003cp\u003eGlobal descriptive statistics for HepB3 vaccine coverage from 1980 to 2023 demonstrate a marked transformation in the global distribution of third-dose hepatitis B vaccination across 204 countries and territories. In the early years (1980\u0026ndash;1982), global coverage was negligible. The mean coverage was 0% in 1980 and 1981, and the median coverage was also 0%, indicating that at least half of all countries reported no measurable uptake. During this period, all 204 countries were classified within the low-coverage category (0\u0026ndash;39%). Even by 1990, global mean coverage had increased only modestly to 8.19%, while the median remained at 0%, and over 90% of countries continued to fall within the low-coverage group. The minimum coverage during this period was consistently 0%, while maximum values gradually increased, reaching above 90% in a small number of countries.\u003c/p\u003e \u003cp\u003eFrom the mid-1990s onward, substantial increases were observed. Between 1995 and 2000, the global mean coverage rose from 22.13% to 41.10%, and the median increased from 0% to 30.20%. By 2002, the median coverage had reached 71.75%, indicating that more than half of all countries had achieved coverage levels above 70%. Over the same interval, the proportion of countries in the high-coverage category (\u0026ge;\u0026thinsp;70%) increased markedly, rising from 21 countries in 1992 to 106 countries by 2002. Correspondingly, the number of countries in the low-coverage category declined substantially. The early 2000s marked a clear shift in global distribution. By 2005, the global mean coverage had reached 68.63%, with a median of 84.80%. At that time, 143 countries (70.1%) were classified as high coverage, while only 42 countries remained in the low-coverage category. This upward trajectory continued through the late 2000s. By 2010, the mean coverage was 78.14%, and the median was 88.85%, with 158 countries (77.5%) in the high-coverage category and only 17 countries in the low category.\u003c/p\u003e \u003cp\u003eFrom 2011 onward, global coverage levels remained relatively stable. Between 2011 and 2023, the mean coverage fluctuated within a narrow range, from approximately 78.6% to 82.1%. The median coverage consistently remained high, ranging between 87% and 89.5%. By 2023, the global mean coverage was 81.82%, and the median was 87.43%. In that year, 171 countries (83.8%) were classified as high coverage, 26 countries (12.7%) as moderate coverage, and 7 countries (3.4%) as low coverage. Measures of dispersion also evolved over time. The interquartile range (IQR) was 0 in the early 1980s, reflecting uniformly low coverage. It expanded substantially during the late 1990s and early 2000s, reaching values above 80 percentage points, before narrowing again in the 2010s to approximately 18\u0026ndash;20 percentage points. The standard deviation followed a similar pattern, peaking during the rapid expansion phase and declining thereafter.\u003c/p\u003e \u003cp\u003eAcross all years combined following vaccine adoption, Albania (Europe) recorded the highest overall HepB3 coverage globally, with a mean coverage of 98.2% over 30 years post-adoption. In contrast, Somalia (Africa) had the lowest overall post-adoption coverage, with a mean of 14.0% across 11 years. Additionally, four countries, Denmark, Finland, Hungary, and Iceland recorded 0% coverage throughout the study period, indicating that they did not adopt the HepB3 vaccine within the timeframe captured by the dataset. The global HepB3 vaccine coverage trends from 1980 to 2023 are corroborated by the choropleth maps in Figs.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e and \u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e, which visually highlight the substantial progress in vaccination coverage over the years, and by the linear mixed-effects regression model which showed that HepB3 vaccination coverage increased by an average of 2.50% per year from 1980 to 2023 (95% CI: 2.41%\u0026ndash;2.59%). This annual increase was found to be statistically significant (p\u0026thinsp;\u0026lt;\u0026thinsp;0.0001). In 1980, the map clearly shows that most countries had negligible coverage, with the majority of regions marked in dark shades, indicating a lack of vaccine access or administration. Fast forward to 2023, and the map reflects the improvements, with the majority of countries now categorized under high coverage (\u0026ge;\u0026thinsp;70%), particularly in Europe, Oceania, and parts of Asia. However, regions such as sub-Saharan Africa and some parts of South Asia still show lower coverage rates, as represented in the map by the green and blue areas for low and moderate coverage, respectively. These visualizations align with the statistical results, confirming the widespread progress, while also highlighting ongoing gaps in coverage across specific geographic regions.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eContinent-level Analysis\u003c/h2\u003e \u003cp\u003eThe continent-level descriptive analysis of HepB3 vaccination coverage from 1980 to 2023 demonstrates pronounced differences in both the timing and magnitude of coverage expansion across world regions. In 1980, all continents recorded an average and median coverage of 0%, reflecting the absence of HepB3 uptake globally at that time. This pattern persisted across regions through much of the 1980s. By 2000, substantial divergence had emerged. As seen in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e, Oceania reported the highest average coverage at 75.6%, with a median of 84.6%, while Asia and Europe recorded moderate average coverage levels of 50.4% and 48.6%, respectively. In contrast, Africa and South America lagged, with average coverages of 15.9% and 29.8%, and median values of 0% and 8.4%, respectively. During this period, within-continent variability was high, particularly in Asia and Europe, where standard deviations exceeded 40 percentage points.\u003c/p\u003e \u003cp\u003eBy 2010, all continents had achieved marked increases in coverage. South America reported the highest average coverage at 88.0%, followed by Asia at 83.4%, North America at 80.4%, and Oceania at 80.2%. Europe and Africa recorded average coverages of 75.4% and 72.0%, respectively. Median coverage exceeded 76% in all continents, with Asia and Europe reporting medians above 90%. Variability declined in most regions, particularly in South America, where the standard deviation fell to 5.6%. In 2023, high coverage levels were sustained across all continents. Asia recorded the highest average coverage at 86.7% (median: 92.5%), followed by Europe at 82.6% (median: 91.9%) and South America at 81.6% (median: 81.8%). Oceania and North America reported similar average coverages of 80.9% and 81.0%, respectively, while Africa recorded the lowest average coverage at 76.5%, despite a median of 82.0%.\u003c/p\u003e \u003cp\u003eThe average HepB3 vaccination coverage trends from 1980 to 2023 across continents in Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e shows a clear upward trajectory for all regions, with significant increases over time. Africa, Asia, Europe, and North America exhibit a steady rise in coverage, with most continents reaching around 80% coverage in recent years. Oceania shows a similar increase, although with some fluctuations. South America follows a similar pattern, reaching a high percentage of coverage in the last two decades. Overall, dispersion continued to narrow across continents, indicating reduced within-region variability by the end of the study period.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eHighest and Lowest Performing Countries by Continent\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"7\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eContinent\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eHighest Performing Country\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eYears After Adoption\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eMean Coverage (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eLowest Performing Country\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eYears After Adoption\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eMean Coverage (%)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAfrica\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eSeychelles\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e29\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e96.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eSomalia\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e14.0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAsia\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eTurkmenistan\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e22\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e97.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eAfghanistan\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e50.1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eEurope\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eAlbania\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e98.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eSwitzerland\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e51.2\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNorth America\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNicaragua\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e96.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eCanada\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e26\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e41.3\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSouth America\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eUruguay\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e92.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eVenezuela (Bolivarian Republic of)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e66.2\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOceania\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eTonga\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e36\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e97.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003ePapua New Guinea\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e35\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e42.1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"4. DISCUSSION","content":"\u003cp\u003eThis study presents findings from the spatiotemporal analysis of HepB3 vaccination coverage across 204 countries and territories from 1980 to 2023. Vaccination rates have increased markedly over the decades, painting an overall positive picture. The ascent from near-zero global mean coverage in 1980 to 81.82% by 2023, with a statistically significant annual increase of 2.50% (95% CI: 2.41%\u0026ndash;2.59%, p\u0026thinsp;\u0026lt;\u0026thinsp;0.0001), represents one of the most remarkable achievements in modern public health. Yet, the progress hasn't been equal. The fact that 33 countries were still classified in the low-to-moderate coverage groups in 2023 shows that much work remains to be done, and that overall optimism should not hide the differences between countries. Some regions and countries have consistently lagged behind, and those gaps are tied to geography, meaning where a child is born still heavily influences whether they get vaccinated.\u003c/p\u003e \u003cp\u003eThe near-zero coverage recorded globally through the early 1980s is consistent with the pre-commercial availability of recombinant hepatitis B vaccines, which only became widely accessible from 1986 onward. The pronounced acceleration observed from the mid-1990s into the early 2000s coincides directly with the establishment of the Global Alliance for Vaccines and Immunization (GAVI) in 2000 and the subsequent mass rollout of the pentavalent combination vaccine in low-income countries. Reductions in vaccine costs and sustained financial and logistical support from Gavi since the early 2000s contributed significantly to expanding vaccine coverage in many low-income countries (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e). The median coverage exceeded 70% by 2002, indicating that more than half of countries had achieved high coverage, supported this interpretation and highlighted the role of international financing mechanisms in accelerating vaccine adoption (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe stabilization of global coverage after 2011, with the mean remaining between 78.6% and 82.1% in the final decade of the study; is both notable and concerning. This suggests that while the early gains from vaccine introduction and global financing have largely been sustained, further progress has been difficult to achieve. This stagnation is not unexpected. Many countries still below the WHO\u0026thinsp;\u0026ge;\u0026thinsp;90% elimination target struggle with uneven vaccine coverage, low completion of the three-dose series, and challenges in conflict-affected or poorly resourced areas (\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e). The interquartile range shrank from over 80 percentage points in the late 1990s to around 18\u0026ndash;20 points by the 2010s, showing that coverage levels are becoming more similar worldwide. However, this progress is uneven, with many countries either reaching high coverage or remaining far below the \u0026ge;\u0026thinsp;90% target.\u003c/p\u003e \u003cp\u003eAt the continental level, gaps in HepB3 coverage remain substantial and carry significant epidemiological implications. Africa\u0026rsquo;s persistently lower coverage, with a continental average of 76.5% in 2023 compared to Asia\u0026rsquo;s 86.7%, should be considered in the context of the continent\u0026rsquo;s disproportionately high burden of hepatitis B infection. Geographic analyses of African HepB3 coverage have documented that continental coverage rose only marginally from 68.06% in 2010 to 69.42% in 2022, with critically low coverage below 40% persisting across the Sahel, the Democratic Republic of the Congo, Angola, and northern Mozambique (\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e). Of the 51 African countries assessed, only six; Rwanda, Eritrea, Eswatini, Burkina Faso, Zimbabwe, and Niger were projected to be on track to meet the 90% coverage target by 2030. This is a sobering indictment of the systemic barriers to vaccine delivery across much of the continent, including inadequate cold chain infrastructure, high rates of out-of-facility births, limited numbers of skilled birth attendants in rural and remote areas, and the logistical challenges inherent in administering vaccines at birth (\u003cspan additionalcitationids=\"CR21\" citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe country-level extremes identified in this study are revealing. Albania had the highest mean coverage globally, reaching 98.2% over 30 years after adopting the vaccine. This success reflects the effectiveness of a well-funded, centralized national immunization program within a functioning healthcare system that benefits from strong political support for childhood vaccination. By contrast, Somalia\u0026rsquo;s average coverage of 14.0% over 11 years reflects the combined effects of prolonged armed conflict, the near-complete breakdown of public health infrastructure, and persistent poverty. Studies of hepatitis B vaccination in Somalia have shown that key barriers to uptake include frequent vaccine unavailability, the high cost of vaccination, and limited awareness of the disease and the benefits of vaccination among at-risk groups (\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eHepB3 was introduced late into Somalia\u0026rsquo;s national routine immunization program, only in 2013 through the pentavalent vaccine. This explains the short post-adoption period reflected in the dataset. Canada's low mean of 41.3% over 26 years presents a different, and perhaps more counterintuitive, case: several high-income European and North American countries, including Denmark, Finland, Hungary, and Iceland, recorded 0% coverage for the entire study period, reflecting deliberate national policy decisions not to adopt universal HepB3 vaccination given their low endemic disease burden. This heterogeneity among high-income countries illustrates that coverage gaps are not exclusively a function of resource constraints; they are also shaped by epidemiological risk perception and public health policy priorities.\u003c/p\u003e \u003cp\u003eThe COVID-19 pandemic caused a major external disruption to routine immunization services, which should be considered when interpreting HepB3 coverage trends from 2020 onward. WHO and UNICEF data confirmed that 23\u0026nbsp;million children missed basic vaccines through routine immunisation services in 2020 alone, 3.7\u0026nbsp;million more than in 2019, with the majority residing in conflict-affected, remote, or informally settled communities (\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e, \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe global routine vaccine doses fell by approximately 30% in April 2020 relative to expected levels, representing the most widespread disruption to immunisation services in recent history (\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e). Research drawing on WHO/UNICEF coverage data showed that vaccine coverage was significantly below predicted levels for 13 of 16 antigens in 2020 and for all assessed antigens in 2021, with the most pronounced shortfalls in South America, Africa, Eastern Europe, and Southeast Asia (\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e). HepB3 coverage remained relatively stable between 2011 and 2023, with only a slight decline in its narrow range. This stability may partly mask disruptions caused by the pandemic, which could become clearer as longer-term data become available.\u003c/p\u003e \u003cp\u003eThe WHO\u0026rsquo;s 2030 target of \u0026ge;\u0026thinsp;90% HepB3 coverage for all member states is theoretically attainable but achieving it will require a change in strategy rather than simply intensifying current efforts. Regional disparities in WHO coverage estimates are substantial, with the Western Pacific region achieved relatively high third-dose hepatitis B (HepB3) coverage, while the Americas and Southeast Asia approaching similar levels, while Africa and the Eastern Mediterranean remain significantly below the global average (\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e). To close existing gaps in hepatitis B prevention, several key actions are required. First, there must be prioritized investment in strengthening health systems within fragile and low-income areas (\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e​A critical step is the accelerated introduction of the hepatitis B birth-dose vaccine across Africa. This is a major priority because, by 2022, only 15 out of 47 member states in the region had adopted universal birth-dose programs (\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e). Additionally, there is a need for targeted interventions in specific districts where vaccination rates remain low despite improvements at the national level. These local gaps are often caused by barriers such as high rates of home births and the logistical difficulty of delivering the vaccine shortly after birth (\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e, \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e). The linear mixed-effects regression results from this study, which identified statistically significant regional and temporal factors influencing HepB3 coverage, support the idea that geography and the policy environment are key, rather than incidental, determinants of vaccination outcomes.\u003c/p\u003e \u003cp\u003eIn summary, global HepB3 vaccination has seen remarkable progress, yet persistent inequities remain. Over the past four decades, many regions have reached near-universal coverage thanks to coordinated investments and strong political commitment (\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e). Despite these achievements, significant gaps continue to exist, especially in Africa, where average coverage is only 76.5%. Inequities are also visible within higher-income regions; for example, Nicaragua reports 96.3% coverage, while Canada lags at 41.3%. Addressing these disparities will require targeted subnational interventions and faster adoption of hepatitis B birth-dose vaccines to ensure that no community is left behind (\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e).\u003c/p\u003e"},{"header":"5. RECOMMENDATIONS AND CONCLUSION","content":"\u003cp\u003eDrawing on the findings of our study, and the broader body of evidence on childhood immunization performance, several policy and programmatic priorities emerge for sustaining progress and addressing the persistent disparities observed in HepB3 vaccine coverage. While global trends demonstrate substantial improvements over the past four decades, targeted and coordinated strategies will be necessary to ensure that these gains translate into equitable protection for children in all regions.\u003c/p\u003e\n\u003cp\u003eOur recommendations are as follows:\u003c/p\u003e\n\u003col start=\"1\" type=\"1\"\u003e\n \u003cli\u003e\u003cstrong\u003eStrengthen National Immunization Policies and Routine Vaccine Delivery Systems:\u003c/strong\u003e\u003cbr\u003e\u0026nbsp;\u003cbr\u003e\u0026nbsp;Governments should continue to prioritize strong national immunization policies that support consistent delivery of routine childhood vaccines, including the hepatitis B third dose. Policy commitments should be matched with adequate financing for immunization programs, improved cold-chain infrastructure, and sustained investment in healthcare workforce capacity (29). Strengthening supply chain management and service delivery platforms will be essential to maintaining high coverage and preventing disruptions in vaccine availability (30).\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003ePrioritize Targeted Interventions in Low-Coverage and Fragile Settings:\u003c/strong\u003e\u003cbr\u003e\u0026nbsp;In the wake of reducing donor-based healthcare spending, it is important that countries and regions with persistently low HepB3 coverage develop context-specific interventions designed to reach populations that remain underserved by routine immunization services. Outreach vaccination campaigns, mobile clinics, and partnerships with local community organizations can play an important role in expanding vaccine access (31). Such approaches are particularly critical in fragile and conflict-affected settings where health system capacity may be limited and help ensure adequate resource utilization.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eIntegrate Hepatitis B Vaccination with Maternal and Child Health Services:\u003c/strong\u003e\u003cbr\u003e\u0026nbsp;Integrating hepatitis B vaccination within broader maternal and child health programs can improve early entry into immunization schedules and increase completion of the recommended vaccine series. Linking vaccination services with antenatal care, delivery services, and postnatal follow-up can strengthen continuity of care and enhance vaccine uptake (32). Particular emphasis should also be placed on improving timely birth-dose administration, especially in settings where facility-based deliveries remain limited.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003ePromote Community Engagement and Strengthen Vaccine Confidence:\u003c/strong\u003e\u003cbr\u003e\u0026nbsp;Sustained improvements in vaccination coverage require strong community trust in immunization programs. Governments and public health institutions should implement culturally appropriate communication strategies that address misinformation, improve public awareness of the benefits of vaccination, and encourage adherence to recommended immunization schedules (33). Engagement with community leaders, healthcare providers, and civil society organizations can further support these efforts.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eStrengthen Surveillance Systems and Data-Driven Decision Making:\u003c/strong\u003e\u003cbr\u003e\u0026nbsp;Robust data systems remain fundamental to effective immunization policy and program planning. Strengthening national health information systems will enable more accurate monitoring of vaccination coverage and facilitate early identification of underserved populations (34). Continued investment in global monitoring frameworks, including the Global Burden of Disease (GBD) estimates and WHO-UNICEF Estimates of National Immunization Coverage (WUENIC), will be essential for tracking progress and informing evidence-based policy responses.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eSustain Global Collaboration and Financing for Immunization Programs:\u003c/strong\u003e\u003cbr\u003e\u0026nbsp;Continued international collaboration will remain critical for supporting countries with limited resources in strengthening their immunization systems. Partnerships involving governments, multilateral organizations, and global health initiatives can provide financial support, technical expertise, and capacity-building opportunities (35). Strengthening these collaborative efforts will be key to reducing inequities in vaccine access and advancing progress toward global immunization targets.\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"CONCLUSION","content":"\u003cp\u003eAs captured by our findings, this study highlights both the remarkable progress achieved in global hepatitis B immunization and the persistent geographic disparities that continue to influence vaccine coverage.In the early years of the study period, HepB3 vaccination coverage was minimal, reflecting the limited availability of hepatitis B vaccines and the absence of widespread immunization policies. The global adoption of universal childhood hepatitis B vaccination strategies in the mid-1990s marked a pivotal turning point, driving a rapid expansion in vaccine uptake over the following decade.\u003c/p\u003e \u003cp\u003eBy 2023, global mean HepB3 coverage had reached approximately 81.8%, with the majority of countries achieving high levels of vaccination coverage. This trajectory reflects the collective impact of sustained immunization initiatives, national policy commitments, and international partnerships dedicated to expanding vaccine access. At the same time, the persistence of lower coverage in parts of sub-Saharan Africa and South Asia underscores the enduring influence of health system constraints, socioeconomic disparities, and logistical barriers to vaccine delivery.\u003c/p\u003e \u003cp\u003eThe global progress observed over the past four decades represents a significant achievement in preventive public health. However, the remaining gaps in coverage make clear that progress has not been evenly distributed. Closing these gaps will require renewed investments in immunization systems, stronger policy implementation, and targeted strategies that prioritize underserved populations.\u003c/p\u003e \u003cp\u003eUltimately, achieving equitable HepB3 coverage is both an attainable goal and an urgent public health imperative. Sustained commitment from national governments, global health institutions, and development partners will be essential to ensure that every child, regardless of geography or circumstance, benefits from the life-saving protection afforded by hepatitis B vaccination.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eETHICS APPROVAL AND CONSENT TO PARTICIPATE.\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;Not Applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eACKNOWLEDGEMENTS.\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot Applicable\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCONSENT FOR PUBLICATION\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot Applicable\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFUNDING STATEMENT.\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNo funding was obtained for this research project.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDECLARATION OF INTERESTS\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll authors declare no competing interest.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCLINICAL TRIAL NUMBER\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDATA AVAILABILITY STATEMENT\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe used data from the Global Burden of Disease Study 2023, and can be found below.\u003c/p\u003e\n\u003cp\u003eInstitute for Health Metrics and Evaluation (IHME). Global Burden of Disease Study 2023 (GBD 2023) Routine Childhood Vaccination Coverage Estimates and Forecasts 1980-2030. Seattle, United States of America: Institute for Health Metrics and Evaluation (IHME), 2025. https://doi.org/10.6069/JCH3-FT68\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u0026nbsp;AUTHORS CONTRIBUTION STATEMENT\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAdewunmi Akingbola conceptualized the study, did the data analysis and wrote the methodology, results and abstracts, Olajumoke Adewole, Maxwell Boakye, Abiodun Adegbesan, Petra Mariaria edited the manuscript, Emmanuella Benson wrote the Discussion, Ozioko wrote the Introduction, Khalil-ur-Rahman wrote the Recommendations and Conclusion. All authors have agreed to this manuscript.\u0026nbsp;\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eImmunization coverage [Internet]. [cited 2026 Mar 9]. Available from: https://www.who.int/news-room/fact-sheets/detail/immunization-coverage\u003c/li\u003e\n\u003cli\u003eReturn On Investment From Childhood Immunization In Low- And Middle-Income Countries, 2011\u0026ndash;20 | Health Affairs [Internet]. [cited 2026 Mar 9]. Available from: https://www.healthaffairs.org/doi/10.1377/hlthaff.2015.1086\u003c/li\u003e\n\u003cli\u003eImmunization Agenda 2030 [Internet]. [cited 2026 Mar 9]. Available from: https://www.who.int/teams/immunization-vaccines-and-biologicals/strategies/ia2030\u003c/li\u003e\n\u003cli\u003e\u0026ldquo;Herd Immunity\u0026rdquo;: A Rough Guide | Clinical Infectious Diseases | Oxford Academic [Internet]. [cited 2026 Mar 9]. Available from: https://academic.oup.com/cid/article/52/7/911/299077\u003c/li\u003e\n\u003cli\u003eBullen M, Heriot GS, Jamrozik E. Herd immunity, vaccination and moral obligation. J Med Ethics. 2023 Sep;49(9):636\u0026ndash;41. doi:10.1136/jme-2022-108485 PubMed PMID: 37277175; PubMed Central PMCID: PMC10511978.\u003c/li\u003e\n\u003cli\u003eHepatitis B vaccines: WHO position paper \u0026ndash; July 2017 [Internet]. [cited 2026 Mar 9]. Available from: https://www.who.int/publications/i/item/WER9227\u003c/li\u003e\n\u003cli\u003ePolaris Observatory Collaborators. Global prevalence, treatment, and prevention of hepatitis B virus infection in 2016: a modelling study. Lancet Gastroenterol Hepatol. 2018 Jun;3(6):383\u0026ndash;403. doi:10.1016/S2468-1253(18)30056-6 PubMed PMID: 29599078.\u003c/li\u003e\n\u003cli\u003eSchillie S, Vellozzi C, Reingold A, Harris A, Haber P, Ward JW, et al. Prevention of Hepatitis B Virus Infection in the United States: Recommendations of the Advisory Committee on Immunization Practices. MMWR Recomm Rep. 2018 Jan 12;67(1):1\u0026ndash;31. doi:10.15585/mmwr.rr6701a1 PubMed PMID: 29939980; PubMed Central PMCID: PMC5837403.\u003c/li\u003e\n\u003cli\u003eImmunization Data [Internet]. [cited 2026 Mar 9]. WHO Immunization Data portal - Global. Available from: https://immunizationdata.who.int\u003c/li\u003e\n\u003cli\u003eFlores JE, Thompson AJ, Ryan M, Howell J. The Global Impact of Hepatitis B Vaccination on Hepatocellular Carcinoma. Vaccines. 2022 May 17;10(5). doi:10.3390/vaccines10050793\u003c/li\u003e\n\u003cli\u003eGlobal progress report on HIV, viral hepatitis and sexually transmitted infections, 2021 [Internet]. [cited 2026 Mar 9]. Available from: https://www.who.int/publications/i/item/9789240027077\u003c/li\u003e\n\u003cli\u003eCausey K, Fullman N, Sorensen RJD, Galles NC, Zheng P, Aravkin A, et al. Estimating global and regional disruptions to routine childhood vaccine coverage during the COVID-19 pandemic in 2020: a modelling study. The Lancet. 2021 Aug 7;398(10299):522\u0026ndash;34. doi:10.1016/S0140-6736(21)01337-4\u003c/li\u003e\n\u003cli\u003eAli HA, Hartner AM, Echeverria-Londono S, Roth J, Li X, Abbas K, et al. Vaccine equity in low and middle income countries: a systematic review and meta-analysis. Int J Equity Health. 2022 Jun 11;21:82. doi:10.1186/s12939-022-01678-5 PubMed PMID: 35701823; PubMed Central PMCID: PMC9194352.\u003c/li\u003e\n\u003cli\u003eSpatial clustering of measles vaccination coverage among children in sub-Saharan Africa | BMC Public Health | Springer Nature Link [Internet]. [cited 2026 Mar 9]. Available from: https://link.springer.com/article/10.1186/s12889-017-4961-9\u003c/li\u003e\n\u003cli\u003eGlobal Burden of Disease (GBD) [Internet]. [cited 2026 Mar 9]. Available from: https://www.healthdata.org/research-analysis/gbd\u003c/li\u003e\n\u003cli\u003eVos T, Lim SS, Abbafati C, Abbas KM, Abbasi M, Abbasifard M, et al. Global burden of 369 diseases and injuries in 204 countries and territories, 1990\u0026ndash;2019: a systematic analysis for the Global Burden of Disease Study 2019. The Lancet. 2020 Oct 17;396(10258):1204\u0026ndash;22. doi:10.1016/S0140-6736(20)30925-9\u003c/li\u003e\n\u003cli\u003eInstitute for Health Metrics and Evaluation. Global Burden of Disease Study 2023 (GBD 2023) Routine Childhood Vaccination Coverage Estimates and Forecasts 1980-2030 [Internet]. Institute for Health Metrics and Evaluation; 2025 [cited 2026 Mar 9]. Available from: https://ghdx.healthdata.org/record/ihme-data/gbd-2023-vaccination-coverage-1980-2030 doi:10.6069/JCH3-FT68\u003c/li\u003e\n\u003cli\u003eAl-Busafi SA, Alwassief A. Global Perspectives on the Hepatitis B Vaccination: Challenges, Achievements, and the Road to Elimination by 2030. Vaccines. 2024 Mar 9;12(3). doi:10.3390/vaccines12030288\u003c/li\u003e\n\u003cli\u003eYu J, Chen X, Li H, Xu Z, Liu Y, Zhang X, et al. Geographic disparities in hepatitis B vaccine coverage across Africa: Implications for targeted interventions and 2030 goals. Journal of Hepatology. 2025 Nov 24. doi:10.1016/j.jhep.2025.11.016\u003c/li\u003e\n\u003cli\u003eBarriers to childhood immunization in sub-Saharan Africa: A systematic review | BMC Public Health | Springer Nature Link [Internet]. [cited 2026 Mar 9]. Available from: https://link.springer.com/article/10.1186/s12889-020-09169-4\u003c/li\u003e\n\u003cli\u003eSolomon-Rakiep T, Olivier J, Amponsah-Dacosta E. Weak Adoption and Performance of Hepatitis B Birth-Dose Vaccination Programs in Africa: Time to Consider Systems Complexity?-A Scoping Review. Trop Med Infect Dis. 2023 Oct 16;8(10):474. doi:10.3390/tropicalmed8100474 PubMed PMID: 37888602; PubMed Central PMCID: PMC10611266.\u003c/li\u003e\n\u003cli\u003eFrontiers | Towards contextualized complex systems approaches to scaling-up hepatitis B birth-dose vaccination in the African region: a qualitative systematic review [Internet]. [cited 2026 Mar 9]. Available from: https://www.frontiersin.org/journals/public-health/articles/10.3389/fpubh.2024.1389633/full\u003c/li\u003e\n\u003cli\u003e\u0026ndash;Tuuryare SAH, Timothy KK, Mohamud MH. Hepatitis B vaccination coverage and associated factors among adults in Somalia: a cross-sectional study. BMC Public Health. 2025 Nov 12;25(1):3917. doi:10.1186/s12889-025-25171-0\u003c/li\u003e\n\u003cli\u003eCOVID-19 pandemic leads to major backsliding on childhood vaccinations, new WHO, UNICEF data shows [Internet]. [cited 2026 Mar 9]. Available from: https://www.unicef.org/press-releases/covid-19-pandemic-leads-major-backsliding-childhood-vaccinations-new-who-unicef-data\u003c/li\u003e\n\u003cli\u003eCOVID-19 pandemic fuels largest continued backslide in vaccinations in three decades [Internet]. [cited 2026 Mar 9]. Available from: https://www.who.int/news/item/15-07-2022-covid-19-pandemic-fuels-largest-continued-backslide-in-vaccinations-in-three-decades\u003c/li\u003e\n\u003cli\u003eGhaznavi C, Eguchi A, Suu Lwin K, Yoneoka D, Tanoue Y, Kumar Rauniyar S, et al. Estimating global changes in routine childhood vaccination coverage during the COVID-19 pandemic, 2020\u0026ndash;2021. Vaccine. 2023 Jun 23;41(28):4151\u0026ndash;7. doi:10.1016/j.vaccine.2023.05.034\u003c/li\u003e\n\u003cli\u003eCGHE [Internet]. [cited 2026 Mar 9]. Introduction of Hepatitis B Birth Dose Vaccination in Africa: A Toolkit for National Immunization Technical Advisory Groups. Available from: https://www.globalhep.org/tools-resources/introduction-hepatitis-b-birth-dose-vaccination-africa-toolkit-national\u003c/li\u003e\n\u003cli\u003eBoisson A, Goel V, Yotebieng M, Parr JB, Fried B, Thompson P. Implementation Approaches for Introducing and Overcoming Barriers to Hepatitis B Birth-Dose Vaccine in sub-Saharan Africa. Global Health: Science and Practice. 2022 Feb 28;10(1). doi:10.9745/GHSP-D-21-00277 PubMed PMID: 35294378.\u003c/li\u003e\n\u003cli\u003eOyugi B, Kallander K, Shahabuddin ASM. Strengthening Primary Health Care Through Implementation Research: Strategies for Reaching Zero-Dose Children in Low- and Middle-Income Countries\u0026rsquo; Immunization Programs. Vaccines (Basel). 2025 Oct 9;13(10):1040. doi:10.3390/vaccines13101040 PubMed PMID: 41150428; PubMed Central PMCID: PMC12568197.\u003c/li\u003e\n\u003cli\u003eMedicine NA of, National Academies of Sciences E, Division H and M, Health B on G, Response C on AI of VD and SC to AP and SIP and, Ashby E, et al. Vaccine Distribution and Delivery. In: Globally Resilient Supply Chains for Seasonal and Pandemic Influenza Vaccines [Internet]. National Academies Press (US); 2021 [cited 2026 Mar 9]. Available from: https://www.ncbi.nlm.nih.gov/books/NBK580009/\u003c/li\u003e\n\u003cli\u003ePennisi F, Genovese C, Gianfredi V. Lessons from the COVID-19 Pandemic: Promoting Vaccination and Public Health Resilience, a Narrative Review. Vaccines (Basel). 2024 Aug 7;12(8):891. doi:10.3390/vaccines12080891 PubMed PMID: 39204017; PubMed Central PMCID: PMC11359644.\u003c/li\u003e\n\u003cli\u003eWilcox CR, Woodward C, Rowe R, Jones CE. Embedding the delivery of antenatal vaccination within routine antenatal care: a key opportunity to improve uptake. Hum Vaccin Immunother. 2019 Jul 24;16(5):1221\u0026ndash;4. doi:10.1080/21645515.2019.1640558 PubMed PMID: 31339429; PubMed Central PMCID: PMC7227681.\u003c/li\u003e\n\u003cli\u003eDickson K, Aboltins C, Pelly J, Jessup RL. Effective communication of COVID-19 vaccine information to recently-arrived culturally and linguistically diverse communities from the perspective of community engagement and partnership organisations: a qualitative study. BMC Health Serv Res. 2023 Aug 21;23:877. doi:10.1186/s12913-023-09836-3 PubMed PMID: 37605184; PubMed Central PMCID: PMC10440864.\u003c/li\u003e\n\u003cli\u003eStockwell MS, Fiks AG. Utilizing health information technology to improve vaccine communication and coverage. Hum Vaccin Immunother. 2013 Aug 1;9(8):1802\u0026ndash;11. doi:10.4161/hv.25031 PubMed PMID: 23807361; PubMed Central PMCID: PMC3906285.\u003c/li\u003e\n\u003cli\u003eArabi S, Butler-Henderson K, Jones S, Vindigni D. Enhancing collaborative international partnerships in healthcare \u0026ndash; a systematic review of insights, challenges, and pathways to sustainability. Social Sciences \u0026amp; Humanities Open. 2025 Jan 1;12:101914. doi:10.1016/j.ssaho.2025.101914\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":false,"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":"discover-public-health","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"","sideBox":"Learn more about [Discover Public Health](https://link.springer.com/journal/12982)","snPcode":"12982","submissionUrl":"https://submission.springernature.com/new-submission/12982/3","title":"Discover Public Health","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Discover Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Hepatitis B, third-dose vaccine, spatiotemporal analysis, global coverage, regression model, choropleth maps","lastPublishedDoi":"10.21203/rs.3.rs-9379366/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9379366/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eIntroduction\u003c/h2\u003e \u003cp\u003eThe Hepatitis B third dose (HepB3) vaccination is essential in preventing chronic infections, liver failure, and cancer. Despite progress, global coverage remains uneven, especially in low-income regions. This study analyzes the global and regional spatiotemporal trends in HepB3 vaccine coverage from 1980\u0026ndash;2023 using the Global Burden of Disease (GBD) 2023 estimates.\u003c/p\u003e\u003ch2\u003eMethodology\u003c/h2\u003e \u003cp\u003eData from GBD 2023, covering 204 countries and territories from 1980 to 2023, was analyzed to assess HepB3 vaccine coverage. Descriptive statistics summarized global and regional trends, and linear mixed-effects regression models evaluated the impact of time and region on coverage. The study also utilized choropleth maps to visualize global and regional coverage variations.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eGlobal coverage increased from near 0% in the 1980s to 81.82% in 2023. Regional disparities were evident, with Europe and Oceania showing higher coverage, while sub-Saharan Africa and South Asia lagged. Regression results indicated an annual increase in coverage of 2.50% (95% CI: 2.41%\u0026ndash;2.59%, p\u0026thinsp;\u0026lt;\u0026thinsp;0.0001). Albania had the highest global coverage at 98.2%, while Somalia had the lowest at 14%.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003eGlobal HepB3 coverage has significantly improved, but geographic disparities persist. Targeted interventions in low-coverage areas and strengthened healthcare systems are needed to meet the 2030 universal coverage goal.\u003c/p\u003e","manuscriptTitle":"Global Spatiotemporal Analysis in Hepatitis B Third Dose Vaccine Coverage from 1980-2023 Across 204 Countries and Territories","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-04-21 08:40:17","doi":"10.21203/rs.3.rs-9379366/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"reviewerAgreed","content":"59723375511988626948242987455616408959","date":"2026-05-16T04:00:24+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-05-08T03:13:22+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2026-04-20T02:31:01+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-04-13T12:21:41+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-04-13T12:21:15+00:00","index":"","fulltext":""},{"type":"submitted","content":"Discover Public Health","date":"2026-04-10T11:52:38+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"discover-public-health","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"","sideBox":"Learn more about [Discover Public Health](https://link.springer.com/journal/12982)","snPcode":"12982","submissionUrl":"https://submission.springernature.com/new-submission/12982/3","title":"Discover Public Health","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Discover Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"5954797b-bae0-45c4-9467-72c7d4d09314","owner":[],"postedDate":"April 21st, 2026","published":true,"recentEditorialEvents":[{"type":"reviewerAgreed","content":"59723375511988626948242987455616408959","date":"2026-05-16T04:00:24+00:00","index":62,"fulltext":""},{"type":"reviewersInvited","content":"40","date":"2026-05-08T03:13:22+00:00","index":"","fulltext":""}],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-05-08T03:25:05+00:00","versionOfRecord":[],"versionCreatedAt":"2026-04-21 08:40:17","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9379366","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9379366","identity":"rs-9379366","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}