Level and trends of zero-dose prevalence children in Mozambique: a repeated cross-sectional analysis of three household surveys, 2011-2023

Level and trends of zero-dose prevalence children in Mozambique: a repeated cross-sectional analysis of three household surveys, 2011-2023 | 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 Level and trends of zero-dose prevalence children in Mozambique: a repeated cross-sectional analysis of three household surveys, 2011-2023 Assucênio Chissaque, Esperança Guimarães, Edmilson Eugénio, Edy Hortêncio Chissaque, and 11 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7538237/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 5 You are reading this latest preprint version Abstract Background: Despite the proven role of childhood immunization in reducing mortality, global coverage targets remain unmet. Zero-dose (ZD) children—those who have not received any dose of the DTP vaccine—remain a critical challenge. Mozambique is among the countries with the lowest vaccination coverage, with full immunization declining from 66% in 2015 to 38% in 2022–2023. This study aims to determine the levels and trends of ZD prevalence in Mozambique. Methods: We analyzed data from three nationally representative surveys—DHS 2011, IMASIDA 2015, and DHS 2022/23—focusing on children aged 12–23 and 24–35 months. The analysis examined trends in ZD prevalence across provinces and explored disparities by urban-rural residence, wealth index, and maternal education. Adjusted prevalence ratios (PRs) and 95% confidence intervals (CIs) were estimated using log-binomial regression. Results: ZD prevalence increased from 5.4% to 14.3% (2015–2022) among children aged 12–23 months and 6.4% to 16.0% among those aged 24–35 months. Key risk factors included rural residence (PR: 0.50; 95% CI: 0.29–0.88 for urban compared to rural), maternal illiteracy (PR: 0.75; 95% CI: 0.61–0.92 for primary education vs. illiteracy), and non-institutional delivery (PR: 0.20; 95% CI: 0.13–0.30 for institutional delivery vs. home birth). The gap in ZD prevalence between the poorest and wealthiest households grew from 11.3 to 26.3 percentage points, and the urban- rural gap grew from 3.9 to 15.3 points. In 2022, children of mothers with no education had a 22.8% ZD prevalence versus 5.4% among those with secondary or higher education. Conclusion: The rising ZD prevalence and widening inequalities underscore the urgent need for targeted, equity-focused interventions. Strengthening health systems to reduce these inequities and improve routine immunization services is essential for improving child health outcomes in Mozambique. Zero-dose Immunization coverage unvaccinated children health inequities Mozambique Repeated cross-sectional analysis Key message What is already known on this topic? Immunization is critical in reducing child mortality, yet the global target of 90% coverage remains unmet, especially in low- and middle-income countries. Zero-dose children, defined as those who have not received any dose of a diphtheria-tetanus-pertussis-containing vaccine (DTP1), remain a persistent challenge, with a global prevalence of 7.7% from 2010 to 2019. Despite improvements in immunization coverage in Mozambique, significant disparities persist due to factors such as geographical inequalities, parental education, and socioeconomic barriers. What this study adds The first comprehensive analysis of zero-dose prevalence trends in Mozambique from 1997 to 2023, using nationally representative surveys. Identifies increasing zero-dose prevalence across all definitions, with disparities between urban and rural areas, wealth quintiles, and maternal education levels. Highlights the role of external factors such as the COVID-19 pandemic and natural disasters in exacerbating zero-dose rates. How this study might affect research, practice, or policy The findings from this study underscore the urgent need to address geographic and socioeconomic disparities to improve immunization coverage in Mozambique. Policymakers can leverage these insights to design targeted interventions in provinces with the highest zero-dose prevalence, such as Zambézia and Tete. The study provides a framework for integrating strategies to mitigate the impacts of external disruptions, such as pandemics and natural disasters, on routine immunization programs. Background Immunization is crucial in preventing and reducing child mortality rates [ 1 , 2 ]. Despite significant progress in increasing immunization coverage, the global target of 90% immunization rate remains unmet [ 2 ]. The World Health Organization (WHO) defines "zero-dose" (ZD) children as those who lack access to or are never reached by routine immunization services. These children are operationally defined as those who have not received their first dose of a diphtheria-tetanus-pertussis (DTP) containing vaccine (DTP1) [ 3 , 4 ]. Overall, an assessment of nationally representative household surveys conducted during the years 2010 to 2019 from 92 low and middle-income countries (LMIC) found a 7.7% prevalence of ZD among children between 12 and 23 months [ 5 ] despite decades of increased global coverage for WHO recommended vaccines [ 6 ]. Many developing countries continue to struggle with low vaccination coverage due to factors such as geopolitical barriers, socioeconomic disparities, conflict zones, and widespread misinformation about vaccines [ 7 , 8 ]. In particular, the COVID-19 pandemic disrupted the routine immunization services, leading to a sharp increase in the number of zero-dose children worldwide [ 9 ], especially in low- and middle-income countries (LMICs) [ 10 ]. For example, Nigeria has seen one of the highest numbers of zero-dose children during this period, with an estimated 2.2 million children missing all vaccines in 2020 [ 11 ]. Similarly, in the Democratic Republic of Congo, around 86,905 children missed the oral polio vaccine, while 74,860 did not receive a dose of the DTP or hepatitis B-Hib3 vaccines that same year [ 12 ]. In Mozambique, there has been documented COVID-19 pandemic-related maternal-child health services disruption, including child immunization, based on model estimates and routine health information system data [ 13 ]. However, these essential sources of information cannot provide the proportion of children in the population that did receive any of the recommended vaccines. This data gap presents a significant challenge for the country's Expanded Program on Immunization (PAV) and broader public health strategies. Zero-dose children complicate immunization program performance, hinder immune response, and contribute to the persistence of outbreaks like poliomyelitis and measles outbreaks, as well as the risk of intussusception from the rotavirus vaccine [ 14 ]. This study aims to examine the proportion of zero-dose children across Mozambique's 11 provinces from 1997 to 2023 and identify factors associated with being zero-dose, using data from three most recent nationally representative household surveys. We assessed the prevalence and trends of zero-dose children in Mozambique, among those aged 12–23 months and 24–35 months. The analysis explored disparities in zero-dose prevalence between urban and rural areas, as well as variations based on maternal education levels and wealth index. Additionally, we examined how household and maternal characteristics influence zero-dose prevalence. The findings will provide insights into the barriers preventing vaccination and inform health policies to improve childhood immunization uptake. Methods Study design and data sources We analyzed data from the three nationally representative household surveys: Demographic and Health Survey (DHS 2011), Inquérito de Indicadores de Imunização, Malária e HIV/SIDA em Moçambique (IMASIDA 2015), and DHS 2022/23. These surveys were designed to collect information on household, maternal, and child health characteristics using a nationally representative complex sampling design. The sampling design included stratification and two-stage sampling. Stratification was based on the 11 provinces and their urban/rural status, resulting in 21 strata. The first stage of sampling involved the demarcation of enumeration areas (ENU), from which clusters of 15–25 households were randomly selected. In the second stage, systematic sampling was applied within these clusters. The surveys gathered data on household characteristics and maternal and child health status through questionnaires administered to women of reproductive age (15–49 years). These women provided information on their household’s sociodemographic, economic, and health status, including maternal and child health, environment, behavior, and prenatal and postnatal care. The survey response rates were high, at 98.9%, 94.5%, 94.3% for women interviewed in the 2011, 2015, and 2022/23 surveys, respectively. Detailed methodology regarding the participant selection process has been described elsewhere [ 15 ]. Study setting Mozambique is a southeastern African country covering 801,590 km 2 , with a population of 34,631,765, the majority (61.2%) of whom live in rural areas. The population grows annually at a rate of 2.5% as of 2023 [ 16 , 17 ]. Children under the age of 5 make up 15.3% of the population, with 17.3% of them in their second year of life. Since gaining independence from Portuguese colonial rule in 1975, Mozambique has faced significant challenges, including a 16-year civil war that devastated its infrastructure and displaced over half of its population [ 18 ] and with increased frequency, it has been fustigated by cyclones and climate change disasters. Mozambique is classified as a low-income country (LIC) by the World Bank, with a gross domestic product (GDP) per capita of USD 1,657.1 in 2023 [ 19 ]. According to the United Nations 2023 Human Development Index, the country ranked 183st out of 193 countries. Mozambique’s EPI began in 1979 with the introduction of Bacillus Calmette-Guérin (BCG), polio, DTP, and measles vaccines [ 20 ]. Over time, more vaccines were added to the national schedule, including an updated DTP vaccine (with additional immunogens for hepatitis B and Haemophilus influenzae type B) in 2008 and a pneumococcal conjugate vaccine (PCV) in 2013. In 2015, the rotavirus vaccine (RV), the injected polio vaccine (IPV), and the second dose of the measles vaccine were introduced. The measles and rubella (MRV) vaccine was introduced in 2019 [ 21 ]. Despite the broader range of vaccines available and improvement in each vaccine's coverage and accessibility, overall full immunization continues to fall short of the EPI target of reaching full immunization coverage of 90%. Outcome The outcome of this study is the zero-dose (ZD) child status, stratified by children aged 12–23 months and 24–35 months. Two definitions of zero-dose are used. The first is based on the WHO’s current recommendations for routine childhood immunizations, which include BCG, polio, DPT and measles-containing vaccines to be administrated in the first year of life [ 16 ]. We define zero-dose as children who did not receive one or more of these four vaccines by the survey date, henceforth referred to as ZDWHO. The second definition follows the Gavi operational definition, which classifies zero-dose children as those who have not received the first dose of the diphtheria-tetanus-pertussis-containing vaccine (DTP1) [ 22 ]. The prevalence of zero-dose is defined as the proportion of children with zero-dose status, henceforth referred to as ZDGavi. Covariates We selected variables based on the literature on maternal-child determinants of health and the availability of data across all surveys. A total of 15 variables were chosen for potential association with the zero-dose status of Mozambican children. The variables included in this analysis were: (1) maternal age at the time of the survey, grouped as 15–24, 25–34 and ≥ 35 years old; (2) maternal educational level, defined as illiterate, primary and secondary or above; (3) marital status, which originally had six categories (single, married, living with a partner, separated, divorced, and widowed) and was recoded into three categories (single/never in a union, married/living with a partner, and divorced/separated/widowed); (4) mother’s occupation, defined as unemployed (not working/household domestic) and employed (professional, clerical, sales, skilled and unskilled manual, services, agriculture, self-employed, and all others); (5) geographic location, where the provinces were included separately and aggregated to reflect the three regions (northern, central, and southern) of the country; (6) area of residence, categorized as urban and rural; (7) wealth index grouped as poorest, poor, middle, richer and richest; (8) total household members (9) religion, categorized differently in each survey but regrouped into four standardized responses across all datasets: Catholic, Islamic, Protestant, and others, which also included no religion; (10) number of antenatal (ANC) visits (no visits, 1 to 3, and ≥ 4); (11) place of delivery (at home/other and at health facility); (12) sex of the child (male and female); (13) birth order (1, 2 to 3, and ≥ 4); and (15) health card possession (seen, not seen, and no card). Data processing and analysis The analysis was stratified by child age at the survey date, with age groups of 12–23 months and 24–35 months. Descriptive statistics were used to summarize child characteristics. We reported the prevalence of ZD children, along with 95% confidence intervals (CI), for each survey and per each definition (ZDWHO and ZDGavi), accounting for the survey sampling design. Changes in ZD prevalence over time were estimated by comparing the ratios of ZD prevalence between 2011 to 2015, and between 2015 to 2022. For these ratios, the delta method was applied to calculate the 95% CI and p-value, testing whether the ratio differed significantly from the null hypothesis (ratio of 1.00). We assessed the association between household, maternal, and child characteristics and ZD prevalence in the 2022/23 survey. Unadjusted and adjusted prevalence ratios (PR) were estimated using log-binomial regression, accounting for the survey design [ 23 ]. Given that potentially many of the characteristics included in the analysis were colinear, we evaluated collinearity using variance inflation factors (VIF). Variables with a VIF greater than 10 were removed from the model. The child vaccination card had the highest VIF (above 30), and the place of delivery and ANC use showed high collinearity, with a VIF close to 20. Therefore, we excluded both the child vaccination card and the ANC use from the model. Additionally, we report two adjusted regression models: one that includes the place of delivery and another that excludes it. The place of delivery serves as a proxy for healthcare access and an opportunity for vaccination-related information to be provided to caregivers. All analyses were conducted in R version 4.4.1 [ 24 ] using the survey package [ 25 ]. Ethics This research was conducted in accordance with the principles of the Declaration of Helsinki and local regulatory requirements. Human Ethics and Consent to Participate declarations: not applicable. Ethical review and approval were waived for this study due to public availability of the data for analysis. Ethical approval was granted by the National Bioethics Committee for Health (CNBS) and written informed consent made available for the 2022/23 survey. Results Sample description The three surveys included a total of 5,263 children aged 12–23 months and 5,026 children aged 24–35 months (Table 1). Approximately three-quarters of children in both age groups lived in rural areas (73.2% and 71.8%, respectively). About one-third of children had illiterate mothers or caregivers (31.5% and 32.7%, respectively), and nearly two-fifths had a mother or caregiver under the age of 25(42.9% and 37.5%, respectively). The majority of mothers or caregivers were either married or cohabiting (83.0% and 82.3%, respectively). While fewer than 10% of children were born to mothers who had no ANC, around one-third of the children (33.8% and 32.5%, respectively) were not born in institutional settings. Of particular note, since 2011, the proportion of children aged 12–23 months without a vaccination card has increased nearly 2.84 times rising from 10.8–30.7%. Similarly, the proportion of children aged 24–35 months without a vaccination card increased from 15.6–40.6%, a 2.60-fold rise (Table 1). Prevalence of zero-dose and time trends Between 2015 and 2022, the overall prevalence of ZDWHO children aged 12–23 months increased from 5.4–14.3% (Table 2), while the ZDGavi prevalence rose from 10.2–24.9% (See additional file 1). These increases corresponded to a 2.64-fold (95% CI: 2.05 to 3.99) and 2.44-fold (95% CI: 2.01 to 2.96) rise, respectively (Tables 3 and additional file 2). Similarly, among the children aged 24–35 months, the ZDWHO prevalence increased from 6.4–16.0% (Table 2), reflecting a 2.52-fold (95% CI: 2.11 to 3.00) increase (Table 3), while the ZDGavi prevalence rose from 13.9–26.5%, a 1.91-fold (95% CI: 1.68 to 2.17) increase. Detailed prevalence estimates using the Gavi operational definition are provided in the additional material (see Additional file 1) and results of time multiplicative changes in zero-dose prevalence using the Gavi operational definition in the additional material (see Additional file 2). From 2011 to 2015, the ZD prevalence among children aged 12–23 months remained relatively stable, with prevalence ratios of 1.09 (95% CI: 0.83 to 1.43) for ZDWHO and 1.08 (95% CI: 0.88 to 1.33) for ZDGavi (Tables 3 and additional file 2). However, for children aged 24–35 months, the ZDGavi prevalence significantly increased by 1.82-fold (from 7.7–13.9%) (See additional files 1 and 2), while the ZDWHO prevalence remained virtually unchanged, rising from 5.5–6.4% (Table 2). The prevalence of ZDWHO among children without vaccination documentation remained virtually unchanged for children aged 12–23 months, from 43.6% (95% CI: 29.2 to 59.3%) in 2015 to 42.2% (95% CI: 35.0 to 49.7%) in 2022 (Tables 2 and 4). For children aged 24–35 months, there was a notable increase from 28.4% (95% CI: 18.0 to 41.6%) in 2015 to 37.2% (95% CI: 32.1 to 42.7%), though this change was not statistically significant. Although at a higher prevalence level, the changes in ZDGavi followed a similar pattern to those in ZDWHO for children 12–23 months without vaccination documentation, from 2015 (57.5%, 95% CI: 43.3 to 70.6%) to 2022 (57.3%, 95% CI: 50.5 to 63.8%). Change in gaps of zero-dose prevalence From 2015 to 2022, there was a differential increase in ZD prevalence across various categories, such as wealth quintiles, area of residence, and maternal education, resulting in widening gaps between these groups (Additional files 1 and 2). Children from poorer households (compared to wealthier households), those living in rural areas (compared to urban areas) and children born to illiterate mothers (compared to those with mothers who had primary, secondary or higher education) experienced the highest increases in ZD prevalence. The gap in ZDWHO prevalence between the 1st to 5th wealth quintiles among children aged 12–23 months grew from 11.3% (12.0 vs. 0.7%) in 2015 to 26.3% (28.2% vs. 1.9%) in 2022. A similar trend was observed for children aged 24–35 months, with the gap increasing from 9.3% in 2015 to 26.5% in 2022. The urban-rural gap in ZDWHO prevalence among children aged 12–23 months expanded from 3.9% (2.5% vs. 6.4%) in 2015 to 15.3% (3.2% vs. 18.5%) in 2022. Among children aged 24–35 months, this gap grew from 3.3% (3.9% vs. 7.2%) to 15.8% (4.9% vs. 20.7%). The gap in ZDWHO prevalence between children aged 12–23 months born to mothers with no education and those born to mothers with secondary or higher education increased from 5.2–17.4%. Similarly, among children aged 24–35 months, this gap expanded from 8.4–23.4%. Factors associated with zero-dose prevalence among children ages 12–23 months Additional Tables 3 and 4 (additional files 3 and 4) namely Unadjusted log-binomial regressions of factors associated with zero-dose prevalence according to WHO and Gavi definitions and Adjusted log-binomial regressions of factors associated with zero-dose prevalence according to WHO and Gavi definitions display the results from log-binomial regression models for ZDWHO prevalence among children aged 12–23 months. The adjusted log-binomial model (excluding the place of delivery) shows that children born to Islamic mothers had a 32% lower prevalence (PR: 0.68, 95% CI: 0.50 to 0.93) of ZDWHO compared to those born to Catholic mothers. No significant differences were observed for other religious denominations. When accounting for place of delivery, the associations remained largely unchanged. Children living in urban areas had a 50% lower ZDWHO prevalence (PR: 0.50, 95% CI: 0.29 to 0.88) compared to those living in rural areas. This association remained virtually unchanged (PR: 0.56, 95% CI: 0.31 to 1.03) even after accounting for place of delivery. Additionally, when factoring in place of delivery, children’s province of residence (compared to Sofala) showed notable variations in ZDWHO prevalence. Children in Niassa (PR: 2.90, 95% CI: 1.34 to 6.27), Nampula (PR: 2.27, 95% CI: 1.02 to 5.05), and Zambézia (PR: 5.66, 95% CI: 2.82 to 11.38) exhibited higher prevalence rates. In the unadjusted model, wealth index quintiles were associated with ZDWHO prevalence, with higher quintiles exhibiting lower prevalence compared to the first quintile. After adjusting for place of delivery, the strength of this association diminished (Table 4). Maternal education level consistently influenced ZDWHO prevalence, regardless of the adjustment of place of delivery. Children born to mothers with primary education had a 25% lower ZDWHO prevalence (PR: 0.75, 95% CI: 0.61 to 0.92) compared to those born to illiterate mothers. Children born to mothers with secondary or higher education had a non-statistically significant 1.22 times higher ZDWHO prevalence (95% CI: 0.88 to 1.70) compared to those born to illiterate mothers. Children born in institutional facilities had an 80% lower prevalence of ZDWHO (PR: 0.20, 95% CI: 0.13 to 0.30) compared to those not born in institutional settings (Table 4). Additional file 1 (unadjusted) and additional file 2 (adjusted) present results from log-binomial regression models for ZDGavi. Although the associations are weaker than for ZDWHO, they follow the same direction and pattern. Factors associated with zero-dose prevalence among children aged 24–35 months After adjustment, factors such as area of residence, province, maternal education, and place of delivery remained statistically significant for ZDWHO prevalence (Table 4). Among children aged 24–35 months, those living in urban areas had a 49% lower ZDWHO prevalence (PR: 0.51, 95% CI: 0.30–0.86) compared to those in rural areas. When compared to Sofala, children in Zambézia, Tete and Nampula had significantly higher ZDWHO prevalence, with prevalence ratios of 4.09 (95% CI: 2.33 to 7.18), 3.44 (95% CI: 1.87 to 6.30), and 1.77 (95% CI: 092 to 3.40), respectively. Children born to mothers with secondary or higher education had a 65% lower ZDWHO prevalence (PR: 0.35, 95% CI: 0.18 to 0.70) compared to those born to illiterate mothers. Children of mothers with primary education showed an 11% lower prevalence (95% CI: 0.69 to 1.16). Additionally, children born in health facilities had a ZDWHO prevalence that was only 33% (PR: 0.33, 95% CI: 0.22 to 0.50) of that for children born at home or outside of health facilities. Discussion Using three nationally representative surveys, we estimated the levels and trends of zero-dose (ZD) prevalence using two definitions: the minimal set of antigens recommended by WHO (ZDWHO), and the Gavi operational definition (ZDGavi). Additionally, we analyzed the predictors of ZD in Mozambique. Between 2015 and 2022, the prevalence of ZDWHO nearly tripled, reaching 14.3% among children 12–23 months and 16.0% among children aged 24–35 months. Furthermore, disparities in ZD prevalence widened between urban and rural areas, as well as across maternal education levels and household wealth quintiles. Several factors contributed to the rise in zero-dose children, including the COVID-19 pandemic, Cyclone Freddy, and cholera outbreaks, as highlighted by Gavi and the WHO. These events led to an increase in the number of unimmunized children and polio resurgence, rising from 97,000 in 2019 to 750,000 by 2023, particularly in the provinces of Zambézia, Nampula, and Tete [ 26 ]. Another contributing factor was the financial crisis triggered by the "hidden debts" scandal, in which government officials borrowed undisclosed substantial sums of money (10% of the GDP) from international banks. This led to the suspension of International Monetary Fund aid and many bilateral and multilateral donors' support, which resulted in a reduction of health sector financial support [ 27 ]. The findings from this analysis are similar to community health surveys conducted in some Sub-Saharan African countries prior to COVID-19, which reported lower zero-dose prevalence rates. For instance, South Africa recorded a national zero-dose prevalence of 9%, Zimbabwe reported 5%, and Malawi 3% [ 28 – 31 ]. Post COVID-19 pandemic, similarly, the ZD prevalence increased as in Nigeria (42%) [ 32 ] and Angola (30%) [ 33 ]. Once more confirming the health service provision disruption driven by the COVID-19 pandemic [ 34 ]. Children in rural areas had the highest prevalence of ZD status. This is most likely due to distance and travel time challenges to access health services particularly in rural areas [ 35 ]. Furhermore, research conducted in rural areas of Gaza and Zambézia provinces has identified several additional barriers to accessing healthcare, including financial constraints, lack of transportation, and poor service quality [ 36 ]. Provincial disparities in ZD prevalence were most pronounced in Zambézia, Tete, and Cabo Delgado, where high poverty levels, inadequate infrastructure, and, in Cabo Delgado’s case, ongoing conflict have disrupted routine health services. These findings align with previous studies highlighting the significant impact of geographic inequities on immunization coverage in Mozambique [ 37 ]. The combination of low vaccination rates and high zero-dose prevalence in these provinces has fueled recurrent outbreaks of polio, cholera, and measles, further threatening public health [ 21 , 26 ]. These provinces also experience some of the highest rates of malnutrition, diarrheal diseases, malaria, inadequate healthcare services, extreme weather events, and the lingering impacts of the COVID-19 pandemic. Moreover, since 2017, political instability in Cabo Delgado, compounded by natural disasters in the central and northern regions, has led to deaths, displacement and social instability. This includes a rise in orphaned children, insufficient healthcare personnel and resources, and increasing social challenges that exacerbate health service inequalities [ 38 ]. These challenges underscore the urgent need for targeted interventions to strengthen primary healthcare services, especially among children, across the county. In response to the increasing prevalence of zero-dose children, the Mozambique EPI launched the first round of the Zero-Dose Children Recovery Initiative in early 2024. This initiative deployed mobile vaccination brigades across 74 districts in Nampula, Niassa, Cabo Delgado, Zambézia, Tete, Manica, and Sofala provinces. The campaign focused on mapping, sensitizing, and mobilizing caregivers to bring children to health units, while mobile brigades were deployed to vaccinate children aged 0 to 59 months in underserved areas [ 39 ]. This analysis revealed that the wealth index was an important predictor of zero-dose prevalence among Mozambican children. Specifically, children from lower-income families were likely of being zero-dose compared to those from better off families. This finding is consistent with previous studies, which have shown that the likelihood of a child being zero-dose increases as family wealth decreases [ 1 , 7 , 40 , 41 ]. Although vaccines are provided free of charge in Mozambique, indirect costs, such as transportation expenses and missing family or outside work, are often borne by mothers and caregivers. These costs can create significant barriers to accessing maternal and child health services, including immunization [ 42 , 43 ]. The number of antenatal care (ANC) visits was a significant predictor of zero-dose status. Children whose mothers had never attended ANC visits exhibited a higher prevalence of being zero-dose compared to those whose mothers attended one to three or more ANC visits. This finding is consistent with previous studies, which have shown that mothers who do not attend health facilities during pregnancy are more likely to have zero-dose children [ 1 , 44 , 45 ]. A possible explanation for this result is Mozambique’s low adherence to ANC visits, which is partially attributed to limited healthcare service coverage in rural areas and long wait times at urban facilities [ 46 , 47 ]. A pilot study conducted in four maternity clinics in Mozambique found that scheduling ANC appointments in advance significantly increased women’s adherence to prenatal visits, highlighting the potential of appointment systems to improve attendance [ 46 ]. The place of delivery was also found to be associated with zero-dose status in children. Children born at home had a higher prevalence of being zero-dose compared to those born in health facilities. This finding aligns with previous studies, which show that children born at home are more likely to remain unvaccinated than those born in healthcare settings [ 1 , 40 , 48 ]. The literature identifies several factors contributing to home births in Mozambique, including overcrowded health facilities, perceptions of inadequate care, and challenges accessing healthcare services. These barriers often discourage women from delivering in healthcare settings, thereby limiting their children’s opportunities for timely vaccination [ 49 ]. While this study significantly contributes to health evidence, its findings should be interpreted considering certain limitations. Firstly, although we did use repeated cross-sectional analysis at the individual level, the analysis is still unprotected from reverse causality between immunization status and the independent variables analyzed. Additionally, data on child immunization were collected from either vaccination cards or similar documents or based on maternal or caregiver recall. This reliance on memory may be subject to recall bias or influenced by the desire to provide socially acceptable responses, which could lead to either over- or underestimation of the number of unvaccinated children. In this study, maternal or caregiver reports were treated as equivalent to data from vaccination cards, potentially affecting the accuracy of the findings. Lastly, as this study was a secondary analysis, exploring key aspects such as knowledge and practices related to vaccination was impossible. This limitation restricted the ability to gain a deeper understanding of the factors associated with zero-dose status, thereby hindering a more comprehensive analysis of the barriers to immunization. Conclusion Between 2015 and 2022, Mozambique saw a troubling threefold increase in the prevalence of zero-dose children (ZDC), with Zambézia and Cabo Delgado provinces experiencing the most significant surge. Antenatal care visits and institutional deliveries were identified as key factors associated with a reduction in ZD prevalence, emphasizing the critical role of these services in ensuring immunization uptake. Other significant factors linked to zero-dose status included birth order, possession of a vaccination card, place of delivery, province of residence, religion, and wealth quintile. These findings underscore the persistent disparities in healthcare access and service delivery, which must be addressed to effectively reduce the prevalence of ZD children. Declarations Acknowledgement The authors would like to thank the parents and guardians who provided survey responses. Special thanks to Augusto Nhacuoanga, the project manager, Claude Pirmez, Maria Julia Gomes de Moura, Gabriel Antonio Rezende de Paula and Júlia Assiat for their support and important discussions during the project implementation. Contributors Conceptualization: AC, OA, EG Data curation: AC, EE, EHC, AP, OA Formal analysis: AC, EE, EHC, AP, OA Visualization: EE, AP, EHC, OA Writing of the original draft: AC, EG, OA writing—review and editing: AC, EG, EE, EHC, AP, CC, BM, LN, AJ, LS, BB, KS, SC, NdD, OA Writing of the review and editing; all authors read and agreed with final version Funding This work was supported by the Bill & Melinda Gates Foundation [INV-008001] and the Brazilian Ministry of Health/DECIT/CNPq [Grand Challenges PALOP]. Under the grant conditions of the Foundation, a Creative Commons Attribution 4.0 Generic License has been assigned to the Author Accepted Manuscript that may result from this submission. Competing interests None declared. Patient and public involvement Patients and/or the public were not involved in the design, conduct, reporting, or dissemination of this research. Patient consent for publication Not applicable. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results. Data availability statement The data used for the analysis is publicly available on the MEASURE/DHS website. References Eryurt MA, Yalçin SS. Zero-dose children in Turkey: regional comparison of pooled data for the period 1990 to 2018. BMC Infect Dis. 2022;22:421. Greenwood B. The contribution of vaccination to global health: past, present and future. Philos Trans R Soc Lond B Biol Sci. 2014;369:20130433. Wonodi C, Farrenkopf BA. Defining the Zero Dose Child: A Comparative Analysis of Two Approaches and Their Impact on Assessing the Zero Dose Burden and Vulnerability Profiles across 82 Low- and Middle-Income Countries. Vaccines. 2023;11:1543. Indicator Metadata Registry Details [Internet]. [cited 2024 Dec 10]. Available from: https://www.who.int/data/gho/indicator-metadata-registry/imr-details/7792 Cata-Preta BO, Santos TM, Mengistu T, Hogan DR, Barros AJD, Victora CG. Zero-dose children and the immunisation cascade: Understanding immunisation pathways in low and middle-income countries. Vaccine. 2021;39:4564–70. Bosch-Capblanch X, Banerjee K, Burton A. Unvaccinated children in years of increasing coverage: how many and who are they? Evidence from 96 low- and middle-income countries. Trop Med Int Health. 2012;17:697–710. Sato R. Zero-Dose, Under-Immunized, and Dropout Children in Nigeria: The Trend and Its Contributing Factors over Time. Vaccines. 2023;11:181. Organization WH. State of the world’s vaccines and immunization [Internet]. World Health Organization; 2009 [cited 2024 Dec 10]. Available from: https://iris.who.int/handle/10665/44169 Castro-Aguirre IE, Alvarez D, Contreras M, Trumbo SP, Mujica OJ, Salas Peraza D, et al. The Impact of the Coronavirus Pandemic on Vaccination Coverage in Latin America and the Caribbean. Vaccines. 2024;12:458. Evans B, Keiser O, Kaiser L, Jombart T. Analysis of global routine immunisation coverage shows disruption and stagnation during the first two-years of the COVID-19 pandemic with tentative recovery in 2022. Vaccine X. 2023;15:100383. Sato R. Geospatial and Time Trend of Prevalence and Characteristics of Zero-Dose Children in Nigeria from 2003 to 2018. Vaccines. 2022;10:1556. Muhoza P. Routine Vaccination Coverage — Worldwide, 2020. MMWR Morb Mortal Wkly Rep [Internet]. 2021 [cited 2024 Dec 10];70. Available from: https://www.cdc.gov/mmwr/volumes/70/wr/mm7043a1.htm Augusto O, Roberton T, Fernandes Q, Chicumbe S, Manhiça I, Tembe S, et al. Early effects of COVID-19 on maternal and child health service disruption in Mozambique. Front Public Health. 2023;11:1075691. Wigley A, Lorin J, Hogan D, Utazi CE, Hagedorn B, Dansereau E, et al. Estimates of the number and distribution of zero-dose and under-immunised children across remote-rural, urban, and conflict-affected settings in low and middle-income countries. PLOS Glob Public Health. 2022;2:e0001126. The DHS Program - Available Datasets [Internet]. [cited 2025 Apr 12]. Available from: https://dhsprogram.com/data/available-datasets.cfm Population Pyramids of the World from 1950 to 2100 [Internet]. PopulationPyramid.net. [cited 2025 Jan 18]. Available from: https://www.populationpyramid.net/ world/2024/ IDS Relatório de Indicadores-Chave [Internet]. INE. [cited 2025 Jan 18]. Available from: https://ine.gov.mz/web/guest/d/ids-relatorio-de-indicadores-chave Chissaque A, Guimarães E, Limaymanta CH, Conjo C, Sebastião Capece BP, Gonçalves L, et al. Post-independence health research productivity in Portuguese-speaking African countries: A bibliometric analysis of 43 years of research and higher education in Mozambique. Heliyon. 2024;10:e35767. World Bank Open Data [Internet]. World Bank Open Data. [cited 2025 Jan 18]. Available from: https://data.worldbank.org Human Development Report 2020 | United Nations iLibrary [Internet]. [cited 2025 Jan 18]. Available from: https://www.un-ilibrary.org/content/books/9789210055161 Cassocera M, Chissaque A, Martins MRO, Deus N de. 40 years of immunization in Mozambique: a narrative review of literature, accomplishments, and perspectives. Cad Saúde Pública [Internet]. 2020;36. Available from: https://doi.org/10.1590%2F0102-311x00038320 Bergen N, Cata-Preta BO, Schlotheuber A, Santos TM, Danovaro-Holliday MC, Mengistu T, et al. Economic-Related Inequalities in Zero-Dose Children: A Study of Non-Receipt of Diphtheria-Tetanus-Pertussis Immunization Using Household Health Survey Data from 89 Low- and Middle-Income Countries. Vaccines. 2022;10:633. Skov T, Deddens J, Petersen MR, Endahl L. Prevalence proportion ratios: estimation and hypothesis testing. Int J Epidemiol. 1998;27:91–5. R: The R Project for Statistical Computing [Internet]. [cited 2025 Jan 18]. Available from: https://www.r-project.org/ Lumley T. Complex surveys: a guide to analysis using R. John Wiley & Sons, Inc; 2010. Mozambique’s grand plan to reach more than 750,000 unimmunised children in 2024 [Internet]. [cited 2025 Jan 11]. Available from: https://www.gavi.org/vaccineswork/mozambiques-grand-plan-reach-over-750000-unimmunised-children-2024 Custos e consequencias das dividas ocultas para Mocambique [Internet]. Maputo, Mocambique: Centro de Integridade Publica and Chr. Michelsen Institute; 2025 Jan. Available from: https://macua.blogs.com/files/cip-custos-e-consequencias-das-dividas-ocultas.pdf The DHS Program - Zimbabwe: DHS, 2015 - Final Report (English) [Internet]. [cited 2025 Jan 18]. Available from: https://dhsprogram.com/publications/publication-fr322-dhs-final-reports.cfm Office/Malawi NS, ICF. Malawi Demographic and Health Survey 2015-16. 2017 [cited 2025 Jan 18]; Available from: https://dhsprogram.com/publications/publication-fr319-dhs-final-reports.cfm The DHS Program - South Africa: Standard DHS, 2016 [Internet]. [cited 2025 Jan 19]. Available from: https://dhsprogram.com/methodology/survey/survey-display-390.cfm Cata-Preta BO, Santos TM, Wendt A, Hogan DR, Mengistu T, Barros AJD, et al. Ethnic disparities in immunisation: analyses of zero-dose prevalence in 64 countries. BMJ Glob Health [Internet]. 2022 [cited 2025 Jan 18];7. Available from: https://gh.bmj.com/content/7/5/e008833 ZDLH_Nigeria_Situation_Analysis_2023.pdf [Internet]. [cited 2025 Jan 19]. Available from: https://zdlh.gavi.org/sites/default/files/2023-12/ZDLH_Nigeria_Situation_Analysis_2023.pdf Zero-dose children in Angola are being protected through a nationwide vaccination campaign | UNICEF [Internet]. [cited 2025 Jan 19]. Available from: https://www.unicef.org/stories/zero-dose-children-in-angola-protected-through-vaccination-campaign Augusto O, Roberton T, Fernandes Q, Chicumbe S, Manhiça I, Tembe S, et al. Early effects of COVID-19 on maternal and child health service disruption in Mozambique. Front Public Health. 2023;11:1075691. dos Anjos Luis A, Cabral P. Geographic accessibility to primary healthcare centers in Mozambique. Int J Equity Health. 2016;15:173. Schwitters A, Lederer P, Zilversmit L, Gudo PS, Ramiro I, Cumba L, et al. Barriers to Health Care in Rural Mozambique: A Rapid Ethnographic Assessment of Planned Mobile Health Clinics for ART. Glob Health Sci Pract. 2015;3:109–16. Egger E-M, Salvucci V, Tarp F. Evolution of Multidimensional Poverty in Crisis-Ridden Mozambique. Soc Indic Res. 2023;166:485–519. When debt and terrorism intersect: the case of Mozambique | ISS Africa [Internet]. [cited 2025 Jan 20]. Available from: https://issafrica.org/iss-today/when-debt-and-terrorism-intersect-the-case-of-mozambique OMS apoiou a recuperação de cerca de 860 mil crianças com Zero Dose e Sub-imunizadas em 74 distritos de Moçambique | OMS | Escritório Regional para a África [Internet]. 2025 [cited 2025 Jan 20]. Available from: https://www.afro.who.int/pt/photo-story/oms-apoiou-recuperacao-de-cerca-de-860-mil-criancas-com-zero-dose-e-sub-imunizadas-em Acharya P, Kismul H, Mapatano MA, Hatløy A. Individual- and community-level determinants of child immunization in the Democratic Republic of Congo: A multilevel analysis. PLoS ONE. 2018;13:e0202742. Johri M, Rajpal S, Subramanian SV. Progress in reaching unvaccinated (zero-dose) children in India, 1992–2016: a multilevel, geospatial analysis of repeated cross-sectional surveys. Lancet Glob Health. 2021;9:e1697–706. Munguambe K, Boene H, Vidler M, Bique C, Sawchuck D, Firoz T, et al. Barriers and facilitators to health care seeking behaviours in pregnancy in rural communities of southern Mozambique. Reprod Health. 2016;13. Child Poverty in Mozambique – Multiple Overlapping Deprivation Analysis | UNICEF [Internet]. 2019 [cited 2025 Jan 20]. Available from: https://www.unicef.org/mozambique/en/reports/child-poverty-mozambique-multiple-overlapping-deprivation-analysis Farrenkopf BA, Zhou X, Shet A, Olayinka F, Carr K, Patenaude B, et al. Understanding household-level risk factors for zero dose immunization in 82 low- and middle-income countries. PLOS ONE. 2023;18:e0287459. Mohamoud SA, Ali-Salad MA, Bile AS, Singh NS, Mahmud AJ, Nor B. Determinants and prevalence of zero-dose children in Somalia: Analysis of the 2020 Health Demographic Survey data. PLOS Glob Public Health. 2024;4:e0002612. Steenland M, Dula J, de Albuquerque A, Fernandes Q, Cuco RM, Chicumbe S, et al. Effects of appointment scheduling on waiting time and utilisation of antenatal care in Mozambique. BMJ Glob Health. 2019;4:e001788. Caregivers in Mozambique share the barriers they face in vaccinating their children [Internet]. [cited 2025 Jan 20]. Available from: https://www.gavi.org/vaccineswork/caregivers-mozambique-share-barriers-they-face-vaccinating-their-children Nchinjoh SC, Saidu Y, Agbor VN, Mbanga CM, Jude Muteh N, Njoh AA, et al. Factors Associated with Zero-Dose Childhood Vaccination Status in a Remote Fishing Community in Cameroon: A Cross-Sectional Analytical Study. Vaccines. 2022;10:2052. Long Q, Madede T, Parkkali S, Chavane L, Sundby J, Hemminki E. Maternity care system in Maputo, Mozambique: Plans and practice? Lee A, editor. Cogent Med. 2017;4:1412138. Tables Tables are available in the Supplementary Files section. Additional Declarations No competing interests reported. Supplementary Files Supplementarymaterials20252108.docx Tables.docx Cite Share Download PDF Status: Under Review Version 1 posted Reviewers invited by journal 10 Oct, 2025 Editor invited by journal 15 Sep, 2025 Editor assigned by journal 13 Sep, 2025 Submission checks completed at journal 13 Sep, 2025 First submitted to journal 04 Sep, 2025 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. 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diphtheria-tetanus-pertussis-containing vaccine (DTP1), remain a persistent challenge, with a global prevalence of 7.7% from 2010 to 2019.\u003c/li\u003e\n \u003cli\u003eDespite improvements in immunization coverage in Mozambique, significant disparities persist due to factors such as geographical inequalities, parental education, and socioeconomic barriers.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003e\u003cstrong\u003eWhat this study adds\u003c/strong\u003e\u003c/p\u003e\n\u003cul type=\"disc\"\u003e\n \u003cli\u003eThe first comprehensive analysis of zero-dose prevalence trends in Mozambique from 1997 to 2023, using nationally representative surveys.\u003c/li\u003e\n \u003cli\u003eIdentifies increasing zero-dose prevalence across all definitions, with disparities between urban and rural areas, wealth quintiles, and maternal education levels.\u003c/li\u003e\n \u003cli\u003eHighlights the role of external factors such as the COVID-19 pandemic and natural disasters in exacerbating zero-dose rates.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003e\u003cstrong\u003eHow this study might affect research, practice, or policy\u003c/strong\u003e\u003c/p\u003e\n\u003cul type=\"disc\"\u003e\n \u003cli\u003eThe findings from this study underscore the urgent need to address geographic and socioeconomic disparities to improve immunization coverage in Mozambique.\u003c/li\u003e\n \u003cli\u003ePolicymakers can leverage these insights to design targeted interventions in provinces with the highest zero-dose prevalence, such as Zamb\u0026eacute;zia and Tete.\u003c/li\u003e\n \u003cli\u003eThe study provides a framework for integrating strategies to mitigate the impacts of external disruptions, such as pandemics and natural disasters, on routine immunization programs.\u003c/li\u003e\n\u003c/ul\u003e"},{"header":"Background","content":"\u003cp\u003eImmunization is crucial in preventing and reducing child mortality rates [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Despite significant progress in increasing immunization coverage, the global target of 90% immunization rate remains unmet [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. The World Health Organization (WHO) defines \"zero-dose\" (ZD) children as those who lack access to or are never reached by routine immunization services. These children are operationally defined as those who have not received their first dose of a diphtheria-tetanus-pertussis (DTP) containing vaccine (DTP1) [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. Overall, an assessment of nationally representative household surveys conducted during the years 2010 to 2019 from 92 low and middle-income countries (LMIC) found a 7.7% prevalence of ZD among children between 12 and 23 months [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e] despite decades of increased global coverage for WHO recommended vaccines [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eMany developing countries continue to struggle with low vaccination coverage due to factors such as geopolitical barriers, socioeconomic disparities, conflict zones, and widespread misinformation about vaccines [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. In particular, the COVID-19 pandemic disrupted the routine immunization services, leading to a sharp increase in the number of zero-dose children worldwide [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e], especially in low- and middle-income countries (LMICs) [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. For example, Nigeria has seen one of the highest numbers of zero-dose children during this period, with an estimated 2.2\u0026nbsp;million children missing all vaccines in 2020 [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. Similarly, in the Democratic Republic of Congo, around 86,905 children missed the oral polio vaccine, while 74,860 did not receive a dose of the DTP or hepatitis B-Hib3 vaccines that same year [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eIn Mozambique, there has been documented COVID-19 pandemic-related maternal-child health services disruption, including child immunization, based on model estimates and routine health information system data [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. However, these essential sources of information cannot provide the proportion of children in the population that did receive any of the recommended vaccines. This data gap presents a significant challenge for the country's Expanded Program on Immunization (PAV) and broader public health strategies. Zero-dose children complicate immunization program performance, hinder immune response, and contribute to the persistence of outbreaks like poliomyelitis and measles outbreaks, as well as the risk of intussusception from the rotavirus vaccine [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eThis study aims to examine the proportion of zero-dose children across Mozambique's 11 provinces from 1997 to 2023 and identify factors associated with being zero-dose, using data from three most recent nationally representative household surveys. We assessed the prevalence and trends of zero-dose children in Mozambique, among those aged 12\u0026ndash;23 months and 24\u0026ndash;35 months. The analysis explored disparities in zero-dose prevalence between urban and rural areas, as well as variations based on maternal education levels and wealth index. Additionally, we examined how household and maternal characteristics influence zero-dose prevalence. The findings will provide insights into the barriers preventing vaccination and inform health policies to improve childhood immunization uptake.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003eStudy design and data sources\u003c/p\u003e\u003cp\u003eWe analyzed data from the three nationally representative household surveys: Demographic and Health Survey (DHS 2011), \u003cem\u003eInqu\u0026eacute;rito de Indicadores de Imuniza\u0026ccedil;\u0026atilde;o, Mal\u0026aacute;ria e HIV/SIDA em Mo\u0026ccedil;ambique\u003c/em\u003e (IMASIDA 2015), and DHS 2022/23. These surveys were designed to collect information on household, maternal, and child health characteristics using a nationally representative complex sampling design. The sampling design included stratification and two-stage sampling. Stratification was based on the 11 provinces and their urban/rural status, resulting in 21 strata. The first stage of sampling involved the demarcation of enumeration areas (ENU), from which clusters of 15\u0026ndash;25 households were randomly selected. In the second stage, systematic sampling was applied within these clusters.\u003c/p\u003e\u003cp\u003eThe surveys gathered data on household characteristics and maternal and child health status through questionnaires administered to women of reproductive age (15\u0026ndash;49 years). These women provided information on their household\u0026rsquo;s sociodemographic, economic, and health status, including maternal and child health, environment, behavior, and prenatal and postnatal care. The survey response rates were high, at 98.9%, 94.5%, 94.3% for women interviewed in the 2011, 2015, and 2022/23 surveys, respectively. Detailed methodology regarding the participant selection process has been described elsewhere [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eStudy setting\u003c/p\u003e\u003cp\u003eMozambique is a southeastern African country covering 801,590 km\u003csup\u003e2\u003c/sup\u003e, with a population of 34,631,765, the majority (61.2%) of whom live in rural areas. The population grows annually at a rate of 2.5% as of 2023 [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. Children under the age of 5 make up 15.3% of the population, with 17.3% of them in their second year of life. Since gaining independence from Portuguese colonial rule in 1975, Mozambique has faced significant challenges, including a 16-year civil war that devastated its infrastructure and displaced over half of its population [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e] and with increased frequency, it has been fustigated by cyclones and climate change disasters. Mozambique is classified as a low-income country (LIC) by the World Bank, with a gross domestic product (GDP) per capita of USD 1,657.1 in 2023 [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. According to the United Nations 2023 Human Development Index, the country ranked 183st out of 193 countries.\u003c/p\u003e\u003cp\u003eMozambique\u0026rsquo;s EPI began in 1979 with the introduction of Bacillus Calmette-Gu\u0026eacute;rin (BCG), polio, DTP, and measles vaccines [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. Over time, more vaccines were added to the national schedule, including an updated DTP vaccine (with additional immunogens for hepatitis B and Haemophilus influenzae type B) in 2008 and a pneumococcal conjugate vaccine (PCV) in 2013. In 2015, the rotavirus vaccine (RV), the injected polio vaccine (IPV), and the second dose of the measles vaccine were introduced. The measles and rubella (MRV) vaccine was introduced in 2019 [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. Despite the broader range of vaccines available and improvement in each vaccine's coverage and accessibility, overall full immunization continues to fall short of the EPI target of reaching full immunization coverage of 90%.\u003c/p\u003e\u003cp\u003eOutcome\u003c/p\u003e\u003cp\u003eThe outcome of this study is the zero-dose (ZD) child status, stratified by children aged 12\u0026ndash;23 months and 24\u0026ndash;35 months. Two definitions of zero-dose are used. The first is based on the WHO\u0026rsquo;s current recommendations for routine childhood immunizations, which include BCG, polio, DPT and measles-containing vaccines to be administrated in the first year of life [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. We define zero-dose as children who did not receive one or more of these four vaccines by the survey date, henceforth referred to as ZDWHO. The second definition follows the Gavi operational definition, which classifies zero-dose children as those who have not received the first dose of the diphtheria-tetanus-pertussis-containing vaccine (DTP1) [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. The prevalence of zero-dose is defined as the proportion of children with zero-dose status, henceforth referred to as ZDGavi.\u003c/p\u003e\u003cp\u003eCovariates\u003c/p\u003e\u003cp\u003eWe selected variables based on the literature on maternal-child determinants of health and the availability of data across all surveys. A total of 15 variables were chosen for potential association with the zero-dose status of Mozambican children. The variables included in this analysis were: (1) maternal age at the time of the survey, grouped as 15\u0026ndash;24, 25\u0026ndash;34 and \u0026ge;\u0026thinsp;35 years old; (2) maternal educational level, defined as illiterate, primary and secondary or above; (3) marital status, which originally had six categories (single, married, living with a partner, separated, divorced, and widowed) and was recoded into three categories (single/never in a union, married/living with a partner, and divorced/separated/widowed); (4) mother\u0026rsquo;s occupation, defined as unemployed (not working/household domestic) and employed (professional, clerical, sales, skilled and unskilled manual, services, agriculture, self-employed, and all others); (5) geographic location, where the provinces were included separately and aggregated to reflect the three regions (northern, central, and southern) of the country; (6) area of residence, categorized as urban and rural; (7) wealth index grouped as poorest, poor, middle, richer and richest; (8) total household members (9) religion, categorized differently in each survey but regrouped into four standardized responses across all datasets: Catholic, Islamic, Protestant, and others, which also included no religion; (10) number of antenatal (ANC) visits (no visits, 1 to 3, and \u0026ge;\u0026thinsp;4); (11) place of delivery (at home/other and at health facility); (12) sex of the child (male and female); (13) birth order (1, 2 to 3, and \u0026ge;\u0026thinsp;4); and (15) health card possession (seen, not seen, and no card).\u003c/p\u003e\u003cp\u003eData processing and analysis\u003c/p\u003e\u003cp\u003eThe analysis was stratified by child age at the survey date, with age groups of 12\u0026ndash;23 months and 24\u0026ndash;35 months. Descriptive statistics were used to summarize child characteristics. We reported the prevalence of ZD children, along with 95% confidence intervals (CI), for each survey and per each definition (ZDWHO and ZDGavi), accounting for the survey sampling design. Changes in ZD prevalence over time were estimated by comparing the ratios of ZD prevalence between 2011 to 2015, and between 2015 to 2022. For these ratios, the delta method was applied to calculate the 95% CI and p-value, testing whether the ratio differed significantly from the null hypothesis (ratio of 1.00).\u003c/p\u003e\u003cp\u003eWe assessed the association between household, maternal, and child characteristics and ZD prevalence in the 2022/23 survey. Unadjusted and adjusted prevalence ratios (PR) were estimated using log-binomial regression, accounting for the survey design [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. Given that potentially many of the characteristics included in the analysis were colinear, we evaluated collinearity using variance inflation factors (VIF). Variables with a VIF greater than 10 were removed from the model. The child vaccination card had the highest VIF (above 30), and the place of delivery and ANC use showed high collinearity, with a VIF close to 20. Therefore, we excluded both the child vaccination card and the ANC use from the model. Additionally, we report two adjusted regression models: one that includes the place of delivery and another that excludes it. The place of delivery serves as a proxy for healthcare access and an opportunity for vaccination-related information to be provided to caregivers. All analyses were conducted in R version 4.4.1 [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e] using the survey package [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eEthics\u003c/p\u003e\u003cp\u003e This research was conducted in accordance with the principles of the Declaration of Helsinki and local regulatory requirements. Human Ethics and Consent to Participate declarations: not applicable. Ethical review and approval were waived for this study due to public availability of the data for analysis. Ethical approval was granted by the National Bioethics Committee for Health (CNBS) and written informed consent made available for the 2022/23 survey.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eSample description\u003c/p\u003e\n\u003cp\u003eThe three surveys included a total of 5,263 children aged 12–23 months and 5,026 children aged 24–35 months (Table\u0026nbsp;1). Approximately three-quarters of children in both age groups lived in rural areas (73.2% and 71.8%, respectively). About one-third of children had illiterate mothers or caregivers (31.5% and 32.7%, respectively), and nearly two-fifths had a mother or caregiver under the age of 25(42.9% and 37.5%, respectively). The majority of mothers or caregivers were either married or cohabiting (83.0% and 82.3%, respectively). While fewer than 10% of children were born to mothers who had no ANC, around one-third of the children (33.8% and 32.5%, respectively) were not born in institutional settings.\u003c/p\u003e\n\u003cdiv\u003e\n\u003c/div\u003e\n\u003cp\u003eOf particular note, since 2011, the proportion of children aged 12–23 months without a vaccination card has increased nearly 2.84 times rising from 10.8–30.7%. Similarly, the proportion of children aged 24–35 months without a vaccination card increased from 15.6–40.6%, a 2.60-fold rise (Table\u0026nbsp;1).\u003c/p\u003e\n\u003cp\u003ePrevalence of zero-dose and time trends\u003c/p\u003e\n\u003cp\u003eBetween 2015 and 2022, the overall prevalence of ZDWHO children aged 12–23 months increased from 5.4–14.3% (Table\u0026nbsp;2), while the ZDGavi prevalence rose from 10.2–24.9% (See additional file 1). These increases corresponded to a 2.64-fold (95% CI: 2.05 to 3.99) and 2.44-fold (95% CI: 2.01 to 2.96) rise, respectively (Tables\u0026nbsp;3 and additional file 2). Similarly, among the children aged 24–35 months, the ZDWHO prevalence increased from 6.4–16.0% (Table\u0026nbsp;2), reflecting a 2.52-fold (95% CI: 2.11 to 3.00) increase (Table\u0026nbsp;3), while the ZDGavi prevalence rose from 13.9–26.5%, a 1.91-fold (95% CI: 1.68 to 2.17) increase. Detailed prevalence estimates using the Gavi operational definition are provided in the additional material (see Additional file 1) and results of time multiplicative changes in zero-dose prevalence using the Gavi operational definition in the additional material (see Additional file 2).\u003c/p\u003e\n\u003cp\u003eFrom 2011 to 2015, the ZD prevalence among children aged 12–23 months remained relatively stable, with prevalence ratios of 1.09 (95% CI: 0.83 to 1.43) for ZDWHO and 1.08 (95% CI: 0.88 to 1.33) for ZDGavi (Tables\u0026nbsp;3 and additional file 2). However, for children aged 24–35 months, the ZDGavi prevalence significantly increased by 1.82-fold (from 7.7–13.9%) (See additional files 1 and 2), while the ZDWHO prevalence remained virtually unchanged, rising from 5.5–6.4% (Table\u0026nbsp;2).\u003c/p\u003e\n\u003cp\u003eThe prevalence of ZDWHO among children without vaccination documentation remained virtually unchanged for children aged 12–23 months, from 43.6% (95% CI: 29.2 to 59.3%) in 2015 to 42.2% (95% CI: 35.0 to 49.7%) in 2022 (Tables\u0026nbsp;2 and 4). For children aged 24–35 months, there was a notable increase from 28.4% (95% CI: 18.0 to 41.6%) in 2015 to 37.2% (95% CI: 32.1 to 42.7%), though this change was not statistically significant. Although at a higher prevalence level, the changes in ZDGavi followed a similar pattern to those in ZDWHO for children 12–23 months without vaccination documentation, from 2015 (57.5%, 95% CI: 43.3 to 70.6%) to 2022 (57.3%, 95% CI: 50.5 to 63.8%).\u003c/p\u003e\n\u003cdiv\u003e\n\u003c/div\u003e\n\u003cp\u003eChange in gaps of zero-dose prevalence\u003c/p\u003e\n\u003cp\u003eFrom 2015 to 2022, there was a differential increase in ZD prevalence across various categories, such as wealth quintiles, area of residence, and maternal education, resulting in widening gaps between these groups (Additional files 1 and 2). Children from poorer households (compared to wealthier households), those living in rural areas (compared to urban areas) and children born to illiterate mothers (compared to those with mothers who had primary, secondary or higher education) experienced the highest increases in ZD prevalence.\u003c/p\u003e\n\u003cp\u003eThe gap in ZDWHO prevalence between the 1st to 5th wealth quintiles among children aged 12–23 months grew from 11.3% (12.0 vs. 0.7%) in 2015 to 26.3% (28.2% vs. 1.9%) in 2022. A similar trend was observed for children aged 24–35 months, with the gap increasing from 9.3% in 2015 to 26.5% in 2022. The urban-rural gap in ZDWHO prevalence among children aged 12–23 months expanded from 3.9% (2.5% vs. 6.4%) in 2015 to 15.3% (3.2% vs. 18.5%) in 2022. Among children aged 24–35 months, this gap grew from 3.3% (3.9% vs. 7.2%) to 15.8% (4.9% vs. 20.7%).\u003c/p\u003e\n\u003cp\u003eThe gap in ZDWHO prevalence between children aged 12–23 months born to mothers with no education and those born to mothers with secondary or higher education increased from 5.2–17.4%. Similarly, among children aged 24–35 months, this gap expanded from 8.4–23.4%.\u003c/p\u003e\n\u003cp\u003eFactors associated with zero-dose prevalence among children ages 12–23 months\u003c/p\u003e\n\u003cp\u003eAdditional Tables 3 and 4 (additional files 3 and 4) namely Unadjusted log-binomial regressions of factors associated with zero-dose prevalence according to WHO and Gavi definitions and Adjusted log-binomial regressions of factors associated with zero-dose prevalence according to WHO and Gavi definitions display the results from log-binomial regression models for ZDWHO prevalence among children aged 12–23 months. The adjusted log-binomial model (excluding the place of delivery) shows that children born to Islamic mothers had a 32% lower prevalence (PR: 0.68, 95% CI: 0.50 to 0.93) of ZDWHO compared to those born to Catholic mothers. No significant differences were observed for other religious denominations. When accounting for place of delivery, the associations remained largely unchanged.\u003c/p\u003e\n\u003cp\u003eChildren living in urban areas had a 50% lower ZDWHO prevalence (PR: 0.50, 95% CI: 0.29 to 0.88) compared to those living in rural areas. This association remained virtually unchanged (PR: 0.56, 95% CI: 0.31 to 1.03) even after accounting for place of delivery. Additionally, when factoring in place of delivery, children’s province of residence (compared to Sofala) showed notable variations in ZDWHO prevalence. Children in Niassa (PR: 2.90, 95% CI: 1.34 to 6.27), Nampula (PR: 2.27, 95% CI: 1.02 to 5.05), and Zambézia (PR: 5.66, 95% CI: 2.82 to 11.38) exhibited higher prevalence rates.\u003c/p\u003e\n\u003cp\u003eIn the unadjusted model, wealth index quintiles were associated with ZDWHO prevalence, with higher quintiles exhibiting lower prevalence compared to the first quintile. After adjusting for place of delivery, the strength of this association diminished (Table\u0026nbsp;4). Maternal education level consistently influenced ZDWHO prevalence, regardless of the adjustment of place of delivery. Children born to mothers with primary education had a 25% lower ZDWHO prevalence (PR: 0.75, 95% CI: 0.61 to 0.92) compared to those born to illiterate mothers. Children born to mothers with secondary or higher education had a non-statistically significant 1.22 times higher ZDWHO prevalence (95% CI: 0.88 to 1.70) compared to those born to illiterate mothers. Children born in institutional facilities had an 80% lower prevalence of ZDWHO (PR: 0.20, 95% CI: 0.13 to 0.30) compared to those not born in institutional settings (Table\u0026nbsp;4).\u003c/p\u003e\n\u003cp\u003eAdditional file 1 (unadjusted) and additional file 2 (adjusted) present results from log-binomial regression models for ZDGavi. Although the associations are weaker than for ZDWHO, they follow the same direction and pattern.\u003c/p\u003e\n\u003cp\u003eFactors associated with zero-dose prevalence among children aged 24–35 months\u003c/p\u003e\n\u003cp\u003eAfter adjustment, factors such as area of residence, province, maternal education, and place of delivery remained statistically significant for ZDWHO prevalence (Table\u0026nbsp;4). Among children aged 24–35 months, those living in urban areas had a 49% lower ZDWHO prevalence (PR: 0.51, 95% CI: 0.30–0.86) compared to those in rural areas. When compared to Sofala, children in Zambézia, Tete and Nampula had significantly higher ZDWHO prevalence, with prevalence ratios of 4.09 (95% CI: 2.33 to 7.18), 3.44 (95% CI: 1.87 to 6.30), and 1.77 (95% CI: 092 to 3.40), respectively. Children born to mothers with secondary or higher education had a 65% lower ZDWHO prevalence (PR: 0.35, 95% CI: 0.18 to 0.70) compared to those born to illiterate mothers. Children of mothers with primary education showed an 11% lower prevalence (95% CI: 0.69 to 1.16). Additionally, children born in health facilities had a ZDWHO prevalence that was only 33% (PR: 0.33, 95% CI: 0.22 to 0.50) of that for children born at home or outside of health facilities.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eUsing three nationally representative surveys, we estimated the levels and trends of zero-dose (ZD) prevalence using two definitions: the minimal set of antigens recommended by WHO (ZDWHO), and the Gavi operational definition (ZDGavi). Additionally, we analyzed the predictors of ZD in Mozambique. Between 2015 and 2022, the prevalence of ZDWHO nearly tripled, reaching 14.3% among children 12\u0026ndash;23 months and 16.0% among children aged 24\u0026ndash;35 months. Furthermore, disparities in ZD prevalence widened between urban and rural areas, as well as across maternal education levels and household wealth quintiles.\u003c/p\u003e\u003cp\u003eSeveral factors contributed to the rise in zero-dose children, including the COVID-19 pandemic, Cyclone Freddy, and cholera outbreaks, as highlighted by Gavi and the WHO. These events led to an increase in the number of unimmunized children and polio resurgence, rising from 97,000 in 2019 to 750,000 by 2023, particularly in the provinces of Zamb\u0026eacute;zia, Nampula, and Tete [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. Another contributing factor was the financial crisis triggered by the \"hidden debts\" scandal, in which government officials borrowed undisclosed substantial sums of money (10% of the GDP) from international banks. This led to the suspension of International Monetary Fund aid and many bilateral and multilateral donors' support, which resulted in a reduction of health sector financial support [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eThe findings from this analysis are similar to community health surveys conducted in some Sub-Saharan African countries prior to COVID-19, which reported lower zero-dose prevalence rates. For instance, South Africa recorded a national zero-dose prevalence of 9%, Zimbabwe reported 5%, and Malawi 3% [\u003cspan additionalcitationids=\"CR29 CR30\" citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e]. Post COVID-19 pandemic, similarly, the ZD prevalence increased as in Nigeria (42%) [\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e] and Angola (30%) [\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e]. Once more confirming the health service provision disruption driven by the COVID-19 pandemic [\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eChildren in rural areas had the highest prevalence of ZD status. This is most likely due to distance and travel time challenges to access health services particularly in rural areas [\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e]. Furhermore, research conducted in rural areas of Gaza and Zamb\u0026eacute;zia provinces has identified several additional barriers to accessing healthcare, including financial constraints, lack of transportation, and poor service quality [\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eProvincial disparities in ZD prevalence were most pronounced in Zamb\u0026eacute;zia, Tete, and Cabo Delgado, where high poverty levels, inadequate infrastructure, and, in Cabo Delgado\u0026rsquo;s case, ongoing conflict have disrupted routine health services. These findings align with previous studies highlighting the significant impact of geographic inequities on immunization coverage in Mozambique [\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e]. The combination of low vaccination rates and high zero-dose prevalence in these provinces has fueled recurrent outbreaks of polio, cholera, and measles, further threatening public health [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e, \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. These provinces also experience some of the highest rates of malnutrition, diarrheal diseases, malaria, inadequate healthcare services, extreme weather events, and the lingering impacts of the COVID-19 pandemic. Moreover, since 2017, political instability in Cabo Delgado, compounded by natural disasters in the central and northern regions, has led to deaths, displacement and social instability. This includes a rise in orphaned children, insufficient healthcare personnel and resources, and increasing social challenges that exacerbate health service inequalities [\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e]. These challenges underscore the urgent need for targeted interventions to strengthen primary healthcare services, especially among children, across the county.\u003c/p\u003e\u003cp\u003eIn response to the increasing prevalence of zero-dose children, the Mozambique EPI launched the first round of the Zero-Dose Children Recovery Initiative in early 2024. This initiative deployed mobile vaccination brigades across 74 districts in Nampula, Niassa, Cabo Delgado, Zamb\u0026eacute;zia, Tete, Manica, and Sofala provinces. The campaign focused on mapping, sensitizing, and mobilizing caregivers to bring children to health units, while mobile brigades were deployed to vaccinate children aged 0 to 59 months in underserved areas [\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eThis analysis revealed that the wealth index was an important predictor of zero-dose prevalence among Mozambican children. Specifically, children from lower-income families were likely of being zero-dose compared to those from better off families. This finding is consistent with previous studies, which have shown that the likelihood of a child being zero-dose increases as family wealth decreases [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e, \u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e]. Although vaccines are provided free of charge in Mozambique, indirect costs, such as transportation expenses and missing family or outside work, are often borne by mothers and caregivers. These costs can create significant barriers to accessing maternal and child health services, including immunization [\u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e, \u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eThe number of antenatal care (ANC) visits was a significant predictor of zero-dose status. Children whose mothers had never attended ANC visits exhibited a higher prevalence of being zero-dose compared to those whose mothers attended one to three or more ANC visits. This finding is consistent with previous studies, which have shown that mothers who do not attend health facilities during pregnancy are more likely to have zero-dose children [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e44\u003c/span\u003e, \u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e]. A possible explanation for this result is Mozambique\u0026rsquo;s low adherence to ANC visits, which is partially attributed to limited healthcare service coverage in rural areas and long wait times at urban facilities [\u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e46\u003c/span\u003e, \u003cspan citationid=\"CR47\" class=\"CitationRef\"\u003e47\u003c/span\u003e]. A pilot study conducted in four maternity clinics in Mozambique found that scheduling ANC appointments in advance significantly increased women\u0026rsquo;s adherence to prenatal visits, highlighting the potential of appointment systems to improve attendance [\u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e46\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eThe place of delivery was also found to be associated with zero-dose status in children. Children born at home had a higher prevalence of being zero-dose compared to those born in health facilities. This finding aligns with previous studies, which show that children born at home are more likely to remain unvaccinated than those born in healthcare settings [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e, \u003cspan citationid=\"CR48\" class=\"CitationRef\"\u003e48\u003c/span\u003e]. The literature identifies several factors contributing to home births in Mozambique, including overcrowded health facilities, perceptions of inadequate care, and challenges accessing healthcare services. These barriers often discourage women from delivering in healthcare settings, thereby limiting their children\u0026rsquo;s opportunities for timely vaccination [\u003cspan citationid=\"CR49\" class=\"CitationRef\"\u003e49\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eWhile this study significantly contributes to health evidence, its findings should be interpreted considering certain limitations. Firstly, although we did use repeated cross-sectional analysis at the individual level, the analysis is still unprotected from reverse causality between immunization status and the independent variables analyzed. Additionally, data on child immunization were collected from either vaccination cards or similar documents or based on maternal or caregiver recall. This reliance on memory may be subject to recall bias or influenced by the desire to provide socially acceptable responses, which could lead to either over- or underestimation of the number of unvaccinated children. In this study, maternal or caregiver reports were treated as equivalent to data from vaccination cards, potentially affecting the accuracy of the findings. Lastly, as this study was a secondary analysis, exploring key aspects such as knowledge and practices related to vaccination was impossible. This limitation restricted the ability to gain a deeper understanding of the factors associated with zero-dose status, thereby hindering a more comprehensive analysis of the barriers to immunization.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eBetween 2015 and 2022, Mozambique saw a troubling threefold increase in the prevalence of zero-dose children (ZDC), with Zamb\u0026eacute;zia and Cabo Delgado provinces experiencing the most significant surge. Antenatal care visits and institutional deliveries were identified as key factors associated with a reduction in ZD prevalence, emphasizing the critical role of these services in ensuring immunization uptake. Other significant factors linked to zero-dose status included birth order, possession of a vaccination card, place of delivery, province of residence, religion, and wealth quintile. These findings underscore the persistent disparities in healthcare access and service delivery, which must be addressed to effectively reduce the prevalence of ZD children.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors would like to thank the parents and guardians who provided survey responses. Special thanks to Augusto Nhacuoanga, the project manager, Claude Pirmez, Maria Julia Gomes de Moura, Gabriel Antonio Rezende de Paula and J\u0026uacute;lia Assiat for their support and important discussions during the project implementation.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eContributors\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eConceptualization: AC, OA, EG\u003c/p\u003e\n\u003cp\u003eData curation: AC, EE, EHC, AP, OA\u003c/p\u003e\n\u003cp\u003eFormal analysis: AC, EE, EHC, AP, OA\u003c/p\u003e\n\u003cp\u003eVisualization: EE, AP, EHC, OA\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eWriting of the original draft: AC, EG, OA\u003c/p\u003e\n\u003cp\u003ewriting\u0026mdash;review and editing: AC, EG, EE, EHC, AP, CC, BM, LN, AJ, LS, BB, KS, SC, NdD, OA\u003c/p\u003e\n\u003cp\u003eWriting of the review and editing; all authors read and agreed with final version\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003cstrong\u003eFunding\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis work was supported by the Bill \u0026amp; Melinda Gates Foundation [INV-008001] and the Brazilian Ministry of Health/DECIT/CNPq [Grand Challenges PALOP]. Under the grant conditions of the Foundation, a Creative Commons Attribution 4.0 Generic License has been assigned to the Author Accepted Manuscript that may result from\u0026nbsp;this\u0026nbsp;submission.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNone declared.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePatient and public involvement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003ePatients and/or the public were not involved in the design, conduct, reporting, or dissemination of this research.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePatient consent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003cstrong\u003eData availability statement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe data used for the analysis is publicly available on the MEASURE/DHS website.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eEryurt MA, Yal\u0026ccedil;in SS. Zero-dose children in Turkey: regional comparison of pooled data for the period 1990 to 2018. BMC Infect Dis. 2022;22:421.\u003c/li\u003e\n\u003cli\u003eGreenwood B. The contribution of vaccination to global health: past, present and future. Philos Trans R Soc Lond B Biol Sci. 2014;369:20130433.\u003c/li\u003e\n\u003cli\u003eWonodi C, Farrenkopf BA. Defining the Zero Dose Child: A Comparative Analysis of Two Approaches and Their Impact on Assessing the Zero Dose Burden and Vulnerability Profiles across 82 Low- and Middle-Income Countries. Vaccines. 2023;11:1543.\u003c/li\u003e\n\u003cli\u003eIndicator Metadata Registry Details [Internet]. [cited 2024 Dec 10]. Available from: https://www.who.int/data/gho/indicator-metadata-registry/imr-details/7792\u003c/li\u003e\n\u003cli\u003eCata-Preta BO, Santos TM, Mengistu T, Hogan DR, Barros AJD, Victora CG. Zero-dose children and the immunisation cascade: Understanding immunisation pathways in low and middle-income countries. Vaccine. 2021;39:4564\u0026ndash;70.\u003c/li\u003e\n\u003cli\u003eBosch-Capblanch X, Banerjee K, Burton A. Unvaccinated children in years of increasing coverage: how many and who are they? Evidence from 96 low- and middle-income countries. Trop Med Int Health. 2012;17:697\u0026ndash;710.\u003c/li\u003e\n\u003cli\u003eSato R. Zero-Dose, Under-Immunized, and Dropout Children in Nigeria: The Trend and Its Contributing Factors over Time. Vaccines. 2023;11:181.\u003c/li\u003e\n\u003cli\u003eOrganization WH. State of the world\u0026rsquo;s vaccines and immunization [Internet]. World Health Organization; 2009 [cited 2024 Dec 10]. Available from: https://iris.who.int/handle/10665/44169\u003c/li\u003e\n\u003cli\u003eCastro-Aguirre IE, Alvarez D, Contreras M, Trumbo SP, Mujica OJ, Salas Peraza D, et al. The Impact of the Coronavirus Pandemic on Vaccination Coverage in Latin America and the Caribbean. Vaccines. 2024;12:458.\u003c/li\u003e\n\u003cli\u003eEvans B, Keiser O, Kaiser L, Jombart T. Analysis of global routine immunisation coverage shows disruption and stagnation during the first two-years of the COVID-19 pandemic with tentative recovery in 2022. Vaccine X. 2023;15:100383.\u003c/li\u003e\n\u003cli\u003eSato R. Geospatial and Time Trend of Prevalence and Characteristics of Zero-Dose Children in Nigeria from 2003 to 2018. Vaccines. 2022;10:1556.\u003c/li\u003e\n\u003cli\u003eMuhoza P. Routine Vaccination Coverage \u0026mdash; Worldwide, 2020. MMWR Morb Mortal Wkly Rep [Internet]. 2021 [cited 2024 Dec 10];70. Available from: https://www.cdc.gov/mmwr/volumes/70/wr/mm7043a1.htm\u003c/li\u003e\n\u003cli\u003eAugusto O, Roberton T, Fernandes Q, Chicumbe S, Manhi\u0026ccedil;a I, Tembe S, et al. Early effects of COVID-19 on maternal and child health service disruption in Mozambique. Front Public Health. 2023;11:1075691.\u003c/li\u003e\n\u003cli\u003eWigley A, Lorin J, Hogan D, Utazi CE, Hagedorn B, Dansereau E, et al. Estimates of the number and distribution of zero-dose and under-immunised children across remote-rural, urban, and conflict-affected settings in low and middle-income countries. PLOS Glob Public Health. 2022;2:e0001126.\u003c/li\u003e\n\u003cli\u003eThe DHS Program - Available Datasets [Internet]. [cited 2025 Apr 12]. Available from: https://dhsprogram.com/data/available-datasets.cfm\u003c/li\u003e\n\u003cli\u003ePopulation Pyramids of the World from 1950 to 2100 [Internet]. PopulationPyramid.net. [cited 2025 Jan 18]. Available from: https://www.populationpyramid.net/ world/2024/\u003c/li\u003e\n\u003cli\u003eIDS Relat\u0026oacute;rio de Indicadores-Chave [Internet]. INE. [cited 2025 Jan 18]. Available from: https://ine.gov.mz/web/guest/d/ids-relatorio-de-indicadores-chave\u003c/li\u003e\n\u003cli\u003eChissaque A, Guimar\u0026atilde;es E, Limaymanta CH, Conjo C, Sebasti\u0026atilde;o Capece BP, Gon\u0026ccedil;alves L, et al. Post-independence health research productivity in Portuguese-speaking African countries: A bibliometric analysis of 43 years of research and higher education in Mozambique. Heliyon. 2024;10:e35767.\u003c/li\u003e\n\u003cli\u003eWorld Bank Open Data [Internet]. World Bank Open Data. [cited 2025 Jan 18]. Available from: https://data.worldbank.org\u003c/li\u003e\n\u003cli\u003eHuman Development Report 2020 | United Nations iLibrary [Internet]. [cited 2025 Jan 18]. Available from: https://www.un-ilibrary.org/content/books/9789210055161\u003c/li\u003e\n\u003cli\u003eCassocera M, Chissaque A, Martins MRO, Deus N de. 40 years of immunization in Mozambique: a narrative review of literature, accomplishments, and perspectives. Cad Sa\u0026uacute;de P\u0026uacute;blica [Internet]. 2020;36. Available from: https://doi.org/10.1590%2F0102-311x00038320\u003c/li\u003e\n\u003cli\u003eBergen N, Cata-Preta BO, Schlotheuber A, Santos TM, Danovaro-Holliday MC, Mengistu T, et al. Economic-Related Inequalities in Zero-Dose Children: A Study of Non-Receipt of Diphtheria-Tetanus-Pertussis Immunization Using Household Health Survey Data from 89 Low- and Middle-Income Countries. Vaccines. 2022;10:633.\u003c/li\u003e\n\u003cli\u003eSkov T, Deddens J, Petersen MR, Endahl L. Prevalence proportion ratios: estimation and hypothesis testing. Int J Epidemiol. 1998;27:91\u0026ndash;5.\u003c/li\u003e\n\u003cli\u003eR: The R Project for Statistical Computing [Internet]. [cited 2025 Jan 18]. Available from: https://www.r-project.org/\u003c/li\u003e\n\u003cli\u003eLumley T. Complex surveys: a guide to analysis using R. John Wiley \u0026amp; Sons, Inc; 2010.\u003c/li\u003e\n\u003cli\u003eMozambique\u0026rsquo;s grand plan to reach more than 750,000 unimmunised children in 2024 [Internet]. [cited 2025 Jan 11]. Available from: https://www.gavi.org/vaccineswork/mozambiques-grand-plan-reach-over-750000-unimmunised-children-2024\u003c/li\u003e\n\u003cli\u003eCustos e consequencias das dividas ocultas para Mocambique [Internet]. Maputo, Mocambique: Centro de Integridade Publica and Chr. Michelsen Institute; 2025 Jan. Available from: https://macua.blogs.com/files/cip-custos-e-consequencias-das-dividas-ocultas.pdf\u003c/li\u003e\n\u003cli\u003eThe DHS Program - Zimbabwe: DHS, 2015 - Final Report (English) [Internet]. [cited 2025 Jan 18]. Available from: https://dhsprogram.com/publications/publication-fr322-dhs-final-reports.cfm\u003c/li\u003e\n\u003cli\u003eOffice/Malawi NS, ICF. Malawi Demographic and Health Survey 2015-16. 2017 [cited 2025 Jan 18]; Available from: https://dhsprogram.com/publications/publication-fr319-dhs-final-reports.cfm\u003c/li\u003e\n\u003cli\u003eThe DHS Program - South Africa: Standard DHS, 2016 [Internet]. [cited 2025 Jan 19]. Available from: https://dhsprogram.com/methodology/survey/survey-display-390.cfm\u003c/li\u003e\n\u003cli\u003eCata-Preta BO, Santos TM, Wendt A, Hogan DR, Mengistu T, Barros AJD, et al. Ethnic disparities in immunisation: analyses of zero-dose prevalence in 64 countries. BMJ Glob Health [Internet]. 2022 [cited 2025 Jan 18];7. Available from: https://gh.bmj.com/content/7/5/e008833\u003c/li\u003e\n\u003cli\u003eZDLH_Nigeria_Situation_Analysis_2023.pdf [Internet]. [cited 2025 Jan 19]. Available from: https://zdlh.gavi.org/sites/default/files/2023-12/ZDLH_Nigeria_Situation_Analysis_2023.pdf\u003c/li\u003e\n\u003cli\u003eZero-dose children in Angola are being protected through a nationwide vaccination campaign | UNICEF [Internet]. [cited 2025 Jan 19]. Available from: https://www.unicef.org/stories/zero-dose-children-in-angola-protected-through-vaccination-campaign\u003c/li\u003e\n\u003cli\u003eAugusto O, Roberton T, Fernandes Q, Chicumbe S, Manhi\u0026ccedil;a I, Tembe S, et al. Early effects of COVID-19 on maternal and child health service disruption in Mozambique. Front Public Health. 2023;11:1075691.\u003c/li\u003e\n\u003cli\u003edos Anjos Luis A, Cabral P. Geographic accessibility to primary healthcare centers in Mozambique. Int J Equity Health. 2016;15:173.\u003c/li\u003e\n\u003cli\u003eSchwitters A, Lederer P, Zilversmit L, Gudo PS, Ramiro I, Cumba L, et al. Barriers to Health Care in Rural Mozambique: A Rapid Ethnographic Assessment of Planned Mobile Health Clinics for ART. Glob Health Sci Pract. 2015;3:109\u0026ndash;16.\u003c/li\u003e\n\u003cli\u003eEgger E-M, Salvucci V, Tarp F. Evolution of Multidimensional Poverty in Crisis-Ridden Mozambique. Soc Indic Res. 2023;166:485\u0026ndash;519.\u003c/li\u003e\n\u003cli\u003eWhen debt and terrorism intersect: the case of Mozambique | ISS Africa [Internet]. [cited 2025 Jan 20]. Available from: https://issafrica.org/iss-today/when-debt-and-terrorism-intersect-the-case-of-mozambique\u003c/li\u003e\n\u003cli\u003eOMS apoiou a recupera\u0026ccedil;\u0026atilde;o de cerca de 860 mil crian\u0026ccedil;as com Zero Dose e Sub-imunizadas em 74 distritos de Mo\u0026ccedil;ambique | OMS | Escrit\u0026oacute;rio Regional para a \u0026Aacute;frica [Internet]. 2025 [cited 2025 Jan 20]. Available from: https://www.afro.who.int/pt/photo-story/oms-apoiou-recuperacao-de-cerca-de-860-mil-criancas-com-zero-dose-e-sub-imunizadas-em\u003c/li\u003e\n\u003cli\u003eAcharya P, Kismul H, Mapatano MA, Hatl\u0026oslash;y A. Individual- and community-level determinants of child immunization in the Democratic Republic of Congo: A multilevel analysis. PLoS ONE. 2018;13:e0202742.\u003c/li\u003e\n\u003cli\u003eJohri M, Rajpal S, Subramanian SV. Progress in reaching unvaccinated (zero-dose) children in India, 1992\u0026ndash;2016: a multilevel, geospatial analysis of repeated cross-sectional surveys. Lancet Glob Health. 2021;9:e1697\u0026ndash;706.\u003c/li\u003e\n\u003cli\u003eMunguambe K, Boene H, Vidler M, Bique C, Sawchuck D, Firoz T, et al. Barriers and facilitators to health care seeking behaviours in pregnancy in rural communities of southern Mozambique. Reprod Health. 2016;13.\u003c/li\u003e\n\u003cli\u003eChild Poverty in Mozambique \u0026ndash; Multiple Overlapping Deprivation Analysis | UNICEF [Internet]. 2019 [cited 2025 Jan 20]. Available from: https://www.unicef.org/mozambique/en/reports/child-poverty-mozambique-multiple-overlapping-deprivation-analysis\u003c/li\u003e\n\u003cli\u003eFarrenkopf BA, Zhou X, Shet A, Olayinka F, Carr K, Patenaude B, et al. Understanding household-level risk factors for zero dose immunization in 82 low- and middle-income countries. PLOS ONE. 2023;18:e0287459.\u003c/li\u003e\n\u003cli\u003eMohamoud SA, Ali-Salad MA, Bile AS, Singh NS, Mahmud AJ, Nor B. Determinants and prevalence of zero-dose children in Somalia: Analysis of the 2020 Health Demographic Survey data. PLOS Glob Public Health. 2024;4:e0002612.\u003c/li\u003e\n\u003cli\u003eSteenland M, Dula J, de Albuquerque A, Fernandes Q, Cuco RM, Chicumbe S, et al. Effects of appointment scheduling on waiting time and utilisation of antenatal care in Mozambique. BMJ Glob Health. 2019;4:e001788.\u003c/li\u003e\n\u003cli\u003eCaregivers in Mozambique share the barriers they face in vaccinating their children [Internet]. [cited 2025 Jan 20]. Available from: https://www.gavi.org/vaccineswork/caregivers-mozambique-share-barriers-they-face-vaccinating-their-children\u003c/li\u003e\n\u003cli\u003eNchinjoh SC, Saidu Y, Agbor VN, Mbanga CM, Jude Muteh N, Njoh AA, et al. Factors Associated with Zero-Dose Childhood Vaccination Status in a Remote Fishing Community in Cameroon: A Cross-Sectional Analytical Study. Vaccines. 2022;10:2052.\u003c/li\u003e\n\u003cli\u003eLong Q, Madede T, Parkkali S, Chavane L, Sundby J, Hemminki E. Maternity care system in Maputo, Mozambique: Plans and practice? Lee A, editor. Cogent Med. 2017;4:1412138.\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003eTables are available in the Supplementary Files section.\u003c/p\u003e\n"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"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":"bmc-pediatrics","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bped","sideBox":"Learn more about [BMC Pediatrics](http://bmcpediatr.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bped/default.aspx","title":"BMC Pediatrics","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Zero-dose, Immunization coverage, unvaccinated children, health inequities, Mozambique, Repeated cross-sectional analysis","lastPublishedDoi":"10.21203/rs.3.rs-7538237/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7538237/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground:\u003c/strong\u003e Despite the proven role of childhood immunization in reducing mortality, global coverage targets remain unmet. Zero-dose (ZD) children—those who have not received any dose of the DTP vaccine—remain a critical challenge. Mozambique is among the countries with the lowest vaccination coverage, with full immunization declining from 66% in 2015 to 38% in 2022–2023. This study aims to determine the levels and trends of ZD prevalence in Mozambique.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods:\u003c/strong\u003e We analyzed data from three nationally representative surveys—DHS 2011, IMASIDA 2015, and DHS 2022/23—focusing on children aged 12–23 and 24–35 months. The analysis examined trends in ZD prevalence across provinces and explored disparities by urban-rural residence, wealth index, and maternal education. Adjusted prevalence ratios (PRs) and 95% confidence intervals (CIs) were estimated using log-binomial regression.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults:\u003c/strong\u003e ZD prevalence increased from 5.4% to 14.3% (2015–2022) among children aged 12–23 months and 6.4% to 16.0% among those aged 24–35 months. Key risk factors included rural residence (PR: 0.50; 95% CI: 0.29–0.88 for urban compared to rural), maternal illiteracy (PR: 0.75; 95% CI: 0.61–0.92 for primary education vs. illiteracy), and non-institutional delivery (PR: 0.20; 95% CI: 0.13–0.30 for institutional delivery vs. home birth). The gap in ZD prevalence between the poorest and wealthiest households grew from 11.3 to 26.3 percentage points, and the urban- rural gap grew from 3.9 to 15.3 points. In 2022, children of mothers with no education had a 22.8% ZD prevalence versus 5.4% among those with secondary or higher education.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion:\u003c/strong\u003e The rising ZD prevalence and widening inequalities underscore the urgent need for targeted, equity-focused interventions. Strengthening health systems to reduce these inequities and improve routine immunization services is essential for improving child health outcomes in Mozambique.\u003c/p\u003e","manuscriptTitle":"Level and trends of zero-dose prevalence children in Mozambique: a repeated cross-sectional analysis of three household surveys, 2011-2023","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-10-23 12:26:09","doi":"10.21203/rs.3.rs-7538237/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"reviewersInvited","content":"","date":"2025-10-10T06:59:02+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2025-09-15T05:08:49+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-09-13T10:16:27+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-09-13T10:15:22+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Pediatrics","date":"2025-09-04T17:01:04+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-pediatrics","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bped","sideBox":"Learn more about [BMC Pediatrics](http://bmcpediatr.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bped/default.aspx","title":"BMC Pediatrics","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"5635dfd1-4c78-46a8-93a8-e6feb010f87f","owner":[],"postedDate":"October 23rd, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2025-10-23T12:26:09+00:00","versionOfRecord":[],"versionCreatedAt":"2025-10-23 12:26:09","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7538237","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7538237","identity":"rs-7538237","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}