Inequalities in full immunization coverage: trends in low- and middle-income countries

The use of community-oriented primary care (COPC) model to generate vaccine demand: The case of a remote fishing community in Cameroon

BACKGROUND

Cameroon, a country in sub-Saharan Africa, ranks among the top 15 countries worldwide with the highest number of zero-dose (unvaccinated) children. Among other reasons, pockets of hard-to-reach communities that traditionally miss essential healthcare services, including childhood immunization, largely contribute to this sub-optimal vaccination coverage. This is the case of Manoka Health District (MHD), an archipelago district with a zero-dose proportion of 91.7%. High disease burdens such as malaria and water-borne diseases have forced the population to depend on herbalists and roadside drug vendors, eroding trust in the primary healthcare system and worsening vaccine hesitancy. This study, therefore, aims to describe how a project optimized vaccine demand generation in these hard-to-reach settlements using an integrated community health worker service delivery package developed using the Community-oriented primary healthcare (COPC) model.

METHODOLOGY

This cross-sectional descriptive study was based on data collected from November 2021 to August 2022 in three project-implementing health areas (Kombo Moukoko, Kooh, and Toube) in the Manoka health district. Data was collected on the integrated health packages offered by Community Health Workers (CHWs). It comprised health education on malaria and water-borne diseases, screening for malaria using Rapid Diagnostic Test (RDT), treatment of under-5 for uncomplicated malaria and diarrhea, conduct of essential Antenatal Care (ANC) services, and vaccination counseling and referral in the three health areas. Microsoft Excel 2013 was used to analyze descriptive data and expressed results as percentages, with tables and column charts used for data visualization. All missing data were considered in the final analysis.

RESULTS

Over 550 under-5 children and 187 pregnant women were identified to be in need of curative and preventive care services during the project period. About 81% of pregnant women received a minimum ANC package by CHWs, and 47% adhered to referrals to health facilities for continuous ANC and delivery. Half of the children under 5 with health issues were diagnosed and managed for uncomplicated malaria. Also, during home visits, 617 under-immunized and zero-dose children less than two years of age were identified, referred, and vaccinated either during an outreach program or at the nearest health post in a neighboring health area, representing about 64% (617/964) of under-2 children identified in these communities. There was a gradual increase from 0% vaccine acceptance post-referral in the first month to 47% after six months and 64% at one year of intervention.

CONCLUSION

The use of the COPC model to co-develop integrated essential health service packages that meet the needs of communities showed value in building trust and increasing childhood immunization uptake in hard-to-reach communities.

Inequality in Childhood Immunization Coverage: A Scoping Review of Data Sources, Analyses, and Reporting Methods

Immunization through vaccines among children has contributed to improved childhood survival and health outcomes globally. However, vaccine coverage among children is unevenly distributed across settings and populations. The measurement of inequalities is essential for understanding gaps in vaccine coverage affecting certain sub-populations and monitoring progress towards achieving equity. Our study aimed to characterize the methods of reporting inequalities in childhood vaccine coverage, inclusive of the settings, data source types, analytical methods, and reporting modalities used to quantify and communicate inequality. We conducted a scoping review of publications in academic journals which included analyses of inequalities in vaccination among children. Literature searches were conducted in PubMed and Web of Science and included relevant articles published between 8 December 2013 and 7 December 2023. Overall, 242 publications were identified, including 204 assessing inequalities in a single country and 38 assessing inequalities across more than one country. We observed that analyses on inequalities in childhood vaccine coverage rely heavily on Demographic Health Survey (DHS) or Multiple Indicator Cluster Surveys (MICS) data (39.3%), and papers leveraging these data had increased in the last decade. Additionally, about half of the single-country studies were conducted in low- and middle-income countries. We found that few studies analyzed and reported inequalities using summary measures of health inequality and largely used the odds ratio resulting from logistic regression models for analyses. The most analyzed dimensions of inequality were economic status and maternal education, and the most common vaccine outcome indicator was full vaccination with the recommended vaccine schedule. However, the definition and construction of both dimensions of inequality and vaccine coverage measures varied across studies, and a variety of approaches were used to study inequalities in vaccine coverage across contexts. Overall, harmonizing methods for selecting and categorizing dimensions of inequalities as well as methods for analyzing and reporting inequalities can improve our ability to assess the magnitude and patterns of inequality in vaccine coverage and compare those inequalities across settings and time.

Decomposition Analysis of Socioeconomic Inequalities in Vaccination Dropout in Remote and Underserved Settings in Ethiopia

Despite increments in immunization coverage over the past decades, substantial inequality due to wealth status has persisted in Ethiopia. This study aimed to decompose the concentration index into the contributions of individual factors to socioeconomic inequalities of childhood vaccination dropout in remote and underserved settings in Ethiopia by using a decomposition approach. A wealth index was developed by reducing 41 variables related to women's household living standards into nine factors by using principal component analysis. The components were further totaled into a composite score and divided into five quintiles (poorest, poorer, middle, richer, and richest). Vaccination dropout was calculated as the proportion of children who did not get the pentavalent-3 vaccine among those who received the pentavalent-1 vaccine. The concentration index was used to estimate socioeconomic inequalities in childhood vaccination dropout, which was then decomposed to examine the factors contributing to socioeconomic inequalities in vaccination dropout. The overall concentration index was -0.179 (P <0.01), confirming the concentration of vaccination dropout among the lowest wealth strata. The decomposition analyses showed that wealth index significantly contributed to inequalities in vaccination dropout (49.7%). Place of residence also explained -16.2% of the inequality. Skilled birth attendance and availability of a health facility in the kebele (the lowest administrative government structure) also significantly contributed (33.6% and 12.6%, respectively) to inequalities in vaccination dropout. Wealth index, place of residence, skilled birth attendance, and availability of a health facility in the kebele largely contributed to the concentration of vaccination dropout among the lowest wealth strata. Policymakers should address vaccination inequality by designing more effective strategies.

Of Money and Men: A Scoping Review to Map Gender Barriers to Immunization Coverage in Low- and Middle-Income Countries

Among the multiple factors impeding equitable childhood immunization coverage in low- and middle-income countries (LMICs), gender barriers stand out as perhaps the most universal. Despite increasing recognition of the importance of gender considerations in immunization programming, there has not yet been a systematic assessment of the evidence on gender barriers to immunization. We conducted a scoping review to fill that gap, identifying 92 articles that described gender barriers to immunization. Studies documented a range of gender influencers across 43 countries in Africa and South Asia. The barrier to immunization coverage most frequently cited in the literature is women's lack of autonomous decision-making. Access to immunization is significantly impacted by women's time poverty; direct costs are also a barrier, particularly when female caregivers rely on family members to cover costs. Challenges with clinic readiness compound female caregiver's time constraints. Some of the most important gender barriers lie outside of the usual purview of immunization programming but other barriers can be addressed with adaptations to vaccination programming. We can only know how important these barriers are with more research that measures the impact of programming on gender barriers to immunization coverage.

Incomplete immunization uptake and associated factors among children aged 12-23 months in sub-Saharan African countries; multilevel analysis evidenced from latest demography and health survey data, 2023

BACKGROUND

In 1974, the World Health Organization (WHO) established the Expanded Program on Immunization to control vaccine-preventable diseases, saving millions of lives annually. However, the coverage of basic vaccines recommended by the WHO in Africa was only 75%, which fell short of the goal of 90% by 2015. To formulate effective policies and implementation programs to reduce incomplete vaccination rates, it is important to conduct a study to determine the factors contributing to incomplete immunization among children aged 12-23 months.

METHODS

The study was conducted in 16 sub-Saharan African countries, using data extracted from the latest DHS data. It was a community-based cross-sectional survey that used two-stage stratified probability sampling sample designs. The vaccination coverage was assessed using vaccination cards and mother recalls. Multilevel multivariable logistic regression was used to determine the extent of incomplete immunization and the individual and community-level factors associated with partial immunization among children aged 12-23 months. Variables with a p-value less than 0.05 were considered statistically significant predictors of incomplete immunization.

RESULT

A total of 35, 193 weighted samples were used to determine the pooled prevalence of partial immunization. The pooled prevalence of incomplete immunization was 36.06%. In the final model factors significantly associated were: being uneducated mother(AOR:1.75;95%CI:1.48,2.05), being an unemployed mother (AOR:1.16;95%CI:1.09,1.23), no history of family planning utilization (AOR: 1.71; 95% CI: 1.61, 1.84), non-antenatal care (AOR: 1.79; 95% CI: 1.58, 2.04), non-postnatal care (AOR: 1.25; 95%CI: 1.17, 1.35), rural residence(AOR:1.50;95%CI:1.37,1.63), home delivery (AOR: 2.04; 95%CI:1.89, 2.21), having children more than five (AOR: 1.56; 95%CI: 1.13, 2.17), and non-utilization of health insurance (AOR: 1.74; 95%CI: 1.48, 2.05).

CONCLUSION

The pooled prevalence of incomplete immunization was found to be high in this investigation. Based on the findings of the study we recommended that policymakers and stakeholders prioritize enhancing prenatal and postnatal care, contraception, and reducing home birth rates to minimize the rate of incomplete immunization.

Child immunization status according to number of siblings and birth order in 85 low- and middle-income countries: a cross-sectional study

Background

Identification of unvaccinated children is important for preventing deaths due to infections. Number of siblings and birth order have been postulated as risk factors for zero-dose prevalence.

Methods

We analysed nationally representative cross-sectional surveys from 85 low and middle-income countries (2010-2020) with information on immunisation status of children aged 12-35 months. Zero-dose prevalence was defined as the failure to receive any doses of DPT (diphtheria-pertussis-tetanus) vaccine. We examined associations with birth order and the number of siblings, adjusting for child's sex, maternal age and education, household wealth quintiles and place of residence. Poisson regression was used to calculate zero-dose prevalence ratios.

Findings

We studied 375,548 children, of whom 13.7% (n = 51,450) were classified as zero-dose. Prevalence increased monotonically with birth order and with the number of siblings, with prevalence increasing from 11.0% for firstborn children to 17.1% for birth order 5 or higher, and from 10.5% for children with no siblings to 17.2% for those with four or more siblings. Adjustment for confounders attenuated but did not eliminate these associations. The number of siblings remained as a strong risk factor when adjusted for confounders and birth order, but the reverse was not observed. Among children with the same number of siblings, there was no clear pattern in zero-dose prevalence by birth order; for instance, among children with two siblings, the prevalence was 13.0%, 14.7%, and 13.3% for firstborn, second, and third-born, respectively. Similar results were observed for girls and boys. 9513 families had two children aged 12-35 months. When the younger sibling was unvaccinated, 61.9% of the older siblings were also unvaccinated. On the other hand, when the younger sibling was vaccinated, only 5.9% of the older siblings were unvaccinated.

Interpretation

The number of siblings is a better predictor than birth order in identifying children to be targeted by immunization campaigns. Zero-dose children tend to be clustered within families.

Funding

Gavi, the Vaccine Alliance.

Reproductive, maternal, newborn, and child health intervention coverage in 70 low-income and middle-income countries, 2000-30: trends, projections, and inequities

BACKGROUND

Monitoring the progress in reproductive, maternal, newborn, and child health (RMNCH) using the composite coverage index (CCI) is crucial to evaluate the advancement of low-income and middle-income countries (LMICs) towards the attainment of Sustainable Development Goal target 3. We present current benchmarking for 70 LMICs, forecasting to 2030, and an analysis of inequities within and across countries.

METHODS

In this cross-sectional secondary data analysis, we extracted 291 data points from the WHO Equity Monitor, and Demographic and Health Survey Statcompiler for 70 LMICs. We selected countries on the basis of whether they belonged to LMICs, had complete information about the predictors between 2000 and 2030, and had at least one data point related to CCI. CCI was calculated on the basis of eight types of RMNCH interventions in four domains, comprising family planning, antenatal care, immunisations, and management of childhood illnesses. This study examined CCI as the main outcome variable. Bayesian hierarchical models were used to estimate trends and projections of the CCI at regional and national levels, as well as the area of residence, educational level, and wealth quintile.

FINDINGS

Despite progress, only 18 countries are projected to reach the 80% CCI target by 2030. Regionally, CCI is projected to increase in all regions of Asia (in southern Asia from 51·8% in 2000 to 89·2% in 2030; in southeastern Asia from 58·8% to 84·4%; in central Asia from 70·3% to 87·0%; in eastern Asia from 76·8% to 82·1%; and in western Asia from 56·5% to 72·1%), Africa (in sub-Saharan Africa from 46·3% in 2000 to 72·2% in 2030 and in northern Africa from 55·0% to 81·7%), and Latin America and the Caribbean (from 67·0% in 2000 to 83·4% in 2030). By contrast, southern Europe is predicted to experience a decline in CCI over the same period (70·1% in 2000 to 55·2% in 2030). Across LMICs, CCIs are higher in urban areas, in populations in which women have higher education levels, and in populations with a high income.

INTERPRETATION

Governments of countries where the universal target of 80% CCI has not yet been reached must develop evidence-based policies aimed at enhancing RMNCH coverage. Additionally, they should focus on reducing the extent of existing inequalities within their populations to drive progress in RMNCH.

FUNDING

Hitotsubashi University and Japan Society for the Promotion of Science.

Vaccination coverage in children under one year of age and associated socioeconomic factors: maps of spatial heterogeneity

OBJECTIVE

to analyze vaccination coverage spatial distribution in children under one year old and the socioeconomic factors associated with meeting the recommended goals in Minas Gerais.

METHODS

an ecological study, carried out in 853 municipalities in the state. Pentavalent, poliomyelitis, meningococcal conjugate, yellow fever, rotavirus, and 10-valent pneumococcal conjugate vaccination coverage were analyzed. Scan statistics and multiple logistic regression were performed to identify spatial clusters and factors associated with meeting coverage goals.

RESULTS

spatial analysis revealed clusters with risk of low coverage for all vaccines. Number of families with per capita income of up to 1/2 wage, Minas Gerais Social Responsibility Index and percentage of the poor or extremely poor population were associated with meeting the established goals.

CONCLUSIONS

the results are useful for designing interventions regarding the structuring of vaccination services and the implementation of actions to increase vaccination coverage in clusters with less propensity to vaccinate.

Perennial malaria chemoprevention with and without malaria vaccination to reduce malaria burden in young children: a modelling analysis

BACKGROUND

A recent WHO recommendation for perennial malaria chemoprevention (PMC) encourages countries to adapt dose timing and number to local conditions. However, knowledge gaps on the epidemiological impact of PMC and possible combination with the malaria vaccine RTS,S hinder informed policy decisions in countries where malaria burden in young children remains high.

METHODS

The EMOD malaria model was used to predict the impact of PMC with and without RTS,S on clinical and severe malaria cases in children under the age of two years (U2). PMC and RTS,S effect sizes were fit to trial data. PMC was simulated with three to seven doses (PMC-3-7) before the age of eighteen months and RTS,S with three doses, shown to be effective at nine months. Simulations were run for transmission intensities of one to 128 infectious bites per person per year, corresponding to incidences of < 1 to 5500 cases per 1000 population U2. Intervention coverage was either set to 80% or based on 2018 household survey data for Southern Nigeria as a sample use case. The protective efficacy (PE) for clinical and severe cases in children U2 was calculated in comparison to no PMC and no RTS,S.

RESULTS

The projected impact of PMC or RTS,S was greater at moderate to high transmission than at low or very high transmission. Across the simulated transmission levels, PE estimates of PMC-3 at 80% coverage ranged from 5.7 to 8.8% for clinical, and from 6.1 to 13.6% for severe malaria (PE of RTS,S 10-32% and 24.6-27.5% for clinical and severe malaria, respectively. In children U2, PMC with seven doses nearly averted as many cases as RTS,S, while the combination of both was more impactful than either intervention alone. When operational coverage, as seen in Southern Nigeria, increased to a hypothetical target of 80%, cases were reduced beyond the relative increase in coverage.

CONCLUSIONS

PMC can substantially reduce clinical and severe cases in the first two years of life in areas with high malaria burden and perennial transmission. A better understanding of the malaria risk profile by age in early childhood and on feasible coverage by age, is needed for selecting an appropriate PMC schedule in a given setting.

Inequalities in child immunization coverage: potential lessons from the Guinea-Bissau case

Immunization is one of the main interventions responsible for the decline in under-5 mortality. This study aimed to assess full immunization coverage trends and related inequalities, according to wealth, area of residence, subnational regions, and maternal schooling level in Guinea-Bissau. Data from the 2006, 2014, and 2018 Guinea-Bissau Multiple Indicator Cluster Surveys (MICS) were analyzed. The slope index of inequality (SII) was estimated by logistic regression for wealth quintiles and maternal schooling level as a measure of absolute inequality. A linear regression model with variance-weighted least squares was used to estimate the annual change of immunization indicators at the national level and for the extremes of wealth, maternal schooling level, and urban-rural areas. Full immunization coverage increased by 1.8p.p./year (95%CI: 1.3; 2.3) over the studied period. Poorer children and children born to uneducated mothers were the most disadvantaged groups. Over the years, wealth inequality decreased and urban-rural inequalities were practically extinguished. In contrast, inequality of maternal schooling level remained unchanged, thus, the highest immunization coverage was among children born to the most educated women. This study shows persistent low immunization coverage and related inequalities in Guinea-Bissau, especially according to maternal schooling level. These findings reinforce the need to adopt equity as a main principle in the development of public health policies to appropriately reduce gaps in immunization and truly leave no one behind in Guinea-Bissau and beyond.

Inequalities in infant vaccination coverage during the COVID-19 pandemic: A population-based study in Peru

OBJECTIVE

To identify the associated factors and assess the inequalities of full vaccination coverage (FVC) among Peruvian infants aged 12-23 months during the COVID-19 pandemic in a nationally representative sample.

METHODS

We carried out a population-based cross-sectional study based on a secondary data analysis using the 2021 Peruvian Demographic Health Survey (DHS) in infants aged 12 to 23 months. The sampling design was probabilistic, multistage, stratified, and independent at both departmental and area of residence levels. FVC was defined according to the WHO definition. We performed generalized linear models (GLM) Poisson family log link function to estimate crude (aPR) and adjusted prevalence ratios (aPR). Also, for inequality assessment, we calculated the concentration curve (CC), concentration index (CI), and Erreygers normalized concentration index (ECI).

RESULTS

We included 4,189 infants in our analysis. Nationwide, the prevalence of FVC was 66.19% (95% CI: 64.33-68). Being younger, having a mother with no education or primary education, belonging to a large family, having no access to mass media, having had six or fewer ANC visits, and having a mother whose age was under 20 at first delivery were inversely associated with FVC. Meanwhile, living in the Highlands or on the rest of the coast, and living in rural areas were directly associated with FVC. We found a pro-rich inequality in FVC based on wealth-ranked households (CI: 0.0066; ECI: 0.0175).

CONCLUSION

FVC has dropped among Peruvian infants aged between 12 and 23 months. There were several factors associated with FVC. It was more concentrated among the better-off infants, although in low magnitude.

Essential childhood immunization in 43 low- and middle-income countries: Analysis of spatial trends and socioeconomic inequalities in vaccine coverage

BACKGROUND

Globally, access to life-saving vaccines has improved considerably in the past 5 decades. However, progress has started to slow down and even reverse in recent years. Understanding subnational heterogeneities in essential child immunization will be critical for closing the global vaccination gap.

METHODS AND FINDINGS

We use vaccination information for over 220,000 children across 1,366 administrative regions in 43 low- and middle-income countries (LMICs) from the most recent Demographic and Health Surveys. We estimate essential immunization coverage at the national and subnational levels and quantify socioeconomic inequalities in such coverage using adjusted concentration indices. Within- and between-country variations are summarized via the Theil index. We use local indicator of spatial association (LISA) statistics to identify clusters of administrative regions with high or low values. Finally, we estimate the number of missed vaccinations among children aged 15 to 35 months across all 43 countries and the types of vaccines most often missed. We show that national-level vaccination rates can conceal wide subnational heterogeneities. Large gaps in child immunization are found across West and Central Africa and in South Asia, particularly in regions of Angola, Chad, Nigeria, Guinea, and Afghanistan, where less than 10% of children are fully immunized. Furthermore, children living in these countries consistently lack all 4 basic vaccines included in the WHO's recommended schedule for young children. Across most countries, children from poorer households are less likely to be fully immunized. The main limitations include subnational estimates based on large administrative divisions for some countries and different periods of survey data collection.

CONCLUSIONS

The identified heterogeneities in essential childhood immunization, especially given that some regions consistently are underserved for all basic vaccines, can be used to inform the design and implementation of localized intervention programs aimed at eliminating child suffering and deaths from existing and novel vaccine-preventable diseases.

Factors Associated with Zero-Dose Childhood Vaccination Status in a Remote Fishing Community in Cameroon: A Cross-Sectional Analytical Study

Background: Cameroon's suboptimal access to childhood vaccinations poses a significant challenge to achieving the Immunization Agenda 2030 goal-ranking among the top 15 countries with a high proportion of zero-dose (unvaccinated) children worldwide. There are clusters of zero-dose children in pockets of communities that traditionally miss essential healthcare services, including vaccination. The Manoka Health District (MHD) is home to such settlements with consistently low vaccination coverages (DPT-HepB-Hib-1: 19.8% in 2021) and frequent outbreaks of vaccine-preventable diseases (VPD). Therefore, the absence of literature on zero-dose children in this context was a clarion call to characterize zero-dose children in fragile settings to inform policy and intervention design. Methodology: This cross-sectional analytical study involved 278 children, 0-24 months of age, selected from a 2020 door-to-door survey conducted in the two most populous health areas in an archipelago rural district, MHD (Cap-Cameroon and Toube). We used R Statistical Software (v4.1.2; R Core Team 2021) to run a multivariable logistic regression to determine zero-dose associated factors. Results: The survey revealed a zero-dose proportion of 91.7% (255) in MHD. Children who were delivered in health facilities were less likely to be zero-dose than those born at home (AOR: 0.07, 95% CI: 0.02-0.30, p = 0.0003). Compared to children born of Christian mothers, children born to minority non-Christian mothers had higher odds of being zero-dose (AOR: 6.55, 95% CI: 1.04-41.25, p = 0.0453). Children born to fathers who are immigrants were more likely to be zero-dose children than Cameroonians (AOR: 2.60, 95% CI = 0.65-10.35, p = 0.0016). Younger children were likely to be unvaccinated compared to older peers (AOR: 0.90, 95% CI: 0.82-1.00, p = 0.0401). Conclusions: In the spirit of "leaving no child behind," the study highlights the need to develop context-specific approaches that consider minority religious groups, immigrants, and younger children, including newborns, often missed during vaccination campaigns and outreaches.

Spatial distribution, determinants and trends of full vaccination coverage in children aged 12-59 months in Peru: A subanalysis of the Peruvian Demographic and Health Survey

OBJECTIVE

To assess the spatial distribution, trends and determinants of crude full vaccination coverage (FVC) in children aged 12-59 months between 2010 and 2019 in Peru.

DESIGN, SETTING AND ANALYSIS

A cross-sectional study based on the secondary data analysis of the 2010 and 2019 Peruvian Demographic and Health Surveys (DHSs) was conducted. Logit based multivariate decomposition analysis was employed to identify factors contributing to differences in FVC between 2010 and 2019. The spatial distribution of FVC in 2019 was evaluated through spatial autocorrelation (Global Moran's I), ordinary kriging interpolation (Gaussian process regression) and Bernoulli-based purely spatial scan statistic.

OUTCOME MEASURE

FVC, as crude coverage, was defined as having completely received BCG; three doses of diphtheria, pertussis, and tetanus, and polio vaccines; and measles vaccine by 12 months of age.

PARTICIPANTS

A total of 5 751 and 14 144 children aged 12-59 months from 2010 and 2019 DHSs, respectively, were included.

RESULTS

FVC increased from 53.62% (95% CI 51.75% to 55.49%) in 2010 to 75.86% (95% CI 74.84% to 76.85%) in 2019. Most of the increase (70.39%) was attributable to differences in coefficients effects. Family size, visit of health workers in the last 12 months, age of the mother at first delivery, place of delivery and antenatal care follow-up were all significantly associated with the increase. The trend of FVC was non-linear and increased by 2.22% annually between 2010 and 2019. FVC distribution was heterogeneous at intradepartmental and interdepartmental level. Seven high-risk clusters of incomplete coverage were identified.

CONCLUSIONS

Although FVC has increased in Peru, it still remains below the recommended threshold. The increase of FVC was mainly attributed to the change in the effects of the characteristics of the population. There was high heterogeneity across Peruvian regions with the presence of high-risk clusters. Interventions must be redirected to reduce these geographical disparities.

Factors associated with diphtheria vaccination completion among children under five years old in Peru 2010-2019: A cross-sectional population-based study

The World Health Organization (WHO) recommends a minimum of 90% coverage of diphtheria three-dose complete vaccination scheme (DPT) as part of routine immunization programs in children. However, diphtheria coverage in Peru has not reached the minimum recommended during the last decades. Our study aimed to determine the complete three-dose DPT coverage and factors associated with compliance towards complete vaccination in Peru between 2010-2019. We conducted a secondary cross-sectional study using the "Encuesta Demográfica y de Salud Familiar (ENDES)"- Demographic and Family Health Survey, which is a survey that targets mothers between 15 and 49 years of age. DPT vaccination coverage was 72.4% and several factors were associated with the DPT scheme completion. Women in the age groups 18 to 24 (ORa = 2.31, 95%CI: 2.11-2.52), 25 to 34 (ORa = 3.37, 95% CI: 3.08-3.69), and 35 to 49 (ORa = 4.74, 95% CI: 4.29-5.22) were more likely to complete their children's DPT vaccination scheme compared to those between 15 to 17 years of age. Both Spanish (ORa = 1.39, 95% CI: 1.31-1.48) and Quechua (ORa = 1.34, 95% CI: 1.25-1.43) as first spoken language were associated with DPT completion compared to native language speaking mothers. Women who worked (ORa = 1.72, 95% CI: 1.57-1.88), studied (ORa = 1.47, 95% CI: 1.33-1.62), or were housewives (ORa = 1.41, 95% CI: 1.29-1.54) during the previous week were more likely to complete their children's DPT scheme compared to participants that did not work during the previous week. Women with the financial capability to access health care were less likely to complete the DPT scheme (ORa = 0.95, 95% CI: 0.92-0.97). Considering the accessibility to health care centers, women who knew the nearest location (ORa = 1.07, 95% CI: 1.03-1.11), had geographic accessibility (ORa = 1.09, 95% CI: 1.06-1.13) or a current transport (ORa = 1.06, 95% CI: 1.02-1.09) were more likely to complete their children 's DPT scheme. Our results highlight low diphtheria vaccine coverage levels in Peru, with values lower than what is recommended by the WHO. Results may serve as a baseline for future studies to improve vaccination programs, reduce barriers and increase DPT coverage in Peru.

Missed Opportunities: A Cross-Sectional Descriptive Study on Reasons for Nonadherence to the South African Expanded Program on Immunization

Objective Our objective was to identify factors which underline nonadherence to childhood immunizations provided by the Department of Health and outlined in the Expanded Program on Immunizations in South Africa.

Methods A cross-sectional descriptive study was conducted at Dora Nginza Hospital, a regional hospital in the Eastern Cape Province, which provides free health care in resource-limited settings. It included patients under the age of 5 years and their primary caregivers. A piloted questionnaire was used to collect data, and comparisons were made between children under the age of 5 years who missed one or more immunizations and those with complete immunizations. Data on maternal/caregiver and health system-related characteristics were also collected, and comparisons were made between the two groups.

Results Of the 200 participants enrolled in the study, 47 (23.5%) had incomplete immunizations. Prematurity (odds ratio [OR] = 0.33, p = 0.001), vaccine shortages (OR = 0.22, p < 0.005), and a low maternal/caregiver level of education (OR = 0.32, p = 0.002) were significantly associated with incomplete immunization status.

Conclusion Strategies to improve supply chain management of vaccines and to optimize follow-up care of high-risk children, specifically those born prematurely and those born to women of lower education level, need to be identified and implemented to reduce vaccine-preventable diseases.

The impact of the Covid-19 pandemic on the uptake of routine maternal and infant vaccines globally: A systematic review

Maintaining routine vaccination coverage is essential to avoid outbreaks of vaccine-preventable diseases. We aimed to understand the international impact of the COVID-19 pandemic on routine vaccination in pregnant women and children aged 0-5-years-old. A systematic review of quantitative and mixed methods studies exploring changes in vaccination coverage, vaccination services, and vaccine confidence since the start of the Covid-19 pandemic was conducted. MEDLINE, EMBASE, CINHAL, PsychINFO, Web of Science, Google Scholar, World Health Organisation, UK Government Joint Committee on Vaccination and Immunisation (including EU and US equivalents), and SAGE Journals were searched between 15-17th June 2021. Selected studies included pregnant women, health professionals, and/or infants aged 0-5-years-old including their parents (population); reported on the Covid-19 pandemic (exposure); presented comparisons with pre-COVID-19 pandemic period (comparator) and reported changes in routine maternal and infant vaccination coverage, services, and confidence (outcomes). Sources published only in non-English language were excluded. The Newcastle Ottawa Scale was used to assess study quality and risk of bias (ROB), and a narrative synthesis was undertaken. This review has been registered with PROSPERO (CRD42021262449). 30 studies were included in the review; data from 20 high-income countries (HICs), seven low- and middle-income countries (LMICs), and three regional studies (groups of countries). 18 studies had a low ROB, 12 had a higher risk, however both low and high ROB studies showed similar results. Two studies meeting the inclusion criteria discussed changes in routine vaccinations for pregnant women while 29 studies discussed infants. Both groups experienced declines in vaccination coverage (up to -79%) with larger disruptions in the accessibility and delivery of vaccination services reported within LMICs compared to HICs. Changes in vaccine confidence remained unclear. The COVID-19 pandemic resulted in decreased vaccine coverage and reduced routine vaccination services for pregnant women and infants, impacts on vaccine confidence requires more research.

Vaccination Status and Its Determinants Among Children Aged 12 to 23 Months in Mettu and Sinana Districts, Oromia Region, Ethiopia: A Comparative Cross Sectional Study

Background

Globally, more than 19 million children have not received all of their vaccination benefits, resulting in an estimated one million deaths worldwide each year. Vaccine-preventable diseases are becoming more common in Ethiopia, despite the fact that official vaccination coverage is sufficient to develop herd immunity locally for some diseases such as measles. This mistrust of the official report prompted us to conduct a community survey and compare it to other areas where there have been no reports of vaccine-preventable disease.

Methods

A community-based comparative cross-sectional study was conducted from 20/01-20/02/2021 in Sinana and Mettu districts. Probability proportional to estimate size was used to select 23 clusters. We recruited 228 from Mettu and 436 from Sinana by systematic random sampling. We used a structured questionnaire to collected data from mother-child pair using card and history. We conducted independent t-tests to test coverage differences between districts. We identified determinants of full vaccination status by multivariate logistic regression analysis after bivariate candidate selection.

Results

Fully vaccinated children accounted for 62.7% in Sinana and 91.6% in Mettu, demonstrating a significant coverage difference (p<0.001). Being a resident of Mettu (AOR: 3.5, 95% CI [1.5, 6.9]), intended pregnancy (AOR 5.9, 95% CI [2.4, 11.3]), 4 or more antenatal care visits (AOR: 2.09, 95% CI [1.4, 3]), having postnatal care (AOR: 3.5, 95% CI [1.6, 7.9]), younger child age (AOR: 0.87, 95% CI [0.8, 0.9]), having up to three children (AOR 3, 95% CI [1.13, 8]) and good knowledge of vaccine schedule (AOR: 2.4, 95% CI [1.4, 4]) were associated positively with full vaccination status.

Conclusion

Full vaccination status was 91.6% in Mettu and 62.7% in Sinana district. Place of residence, ANC, PNC, pregnancy intention, child number, age of child and knowledge of vaccination schedule were significantly associated with vaccination status of the children.

Madagascar's EPI vaccine programs: A systematic review uncovering the role of a child's sex and other barriers to vaccination

Background

Immunizations are one of the most effective tools a community can use to increase overall health and decrease the burden of vaccine-preventable diseases. Nevertheless, socioeconomic status, geographical location, education, and a child's sex have been identified as contributing to inequities in vaccine uptake in low- and middle-income countries (LMICs). Madagascar follows the World Health Organization's Extended Programme on Immunization (EPI) schedule, yet vaccine distribution remains highly inequitable throughout the country. This systematic review sought to understand the differences in EPI vaccine uptake between boys and girls in Madagascar.

Methods

A systematic literature search was conducted in August 2021 through MEDLINE, the Cochrane Library, Global Index Medicus, and Google Scholar to identify articles reporting sex-disaggregated vaccination rates in Malagasy children. Gray literature was also searched for relevant data. All peer-reviewed articles reporting sex-disaggregated data on childhood immunizations in Madagascar were eligible for inclusion. Risk of bias was assessed using a tool designed for use in systematic reviews. Data extraction was conducted with a pre-defined data extraction tool. Sex-disaggregated data were synthesized to understand the impact of a child's sex on vaccination status.

Findings

The systematic search identified 585 articles of which a total of three studies were included in the final data synthesis. One additional publication was included from the gray literature search. Data from included articles were heterogeneous and, overall, indicated similar vaccination rates in boys and girls. Three of the four articles reported slightly higher vaccination rates in girls than in boys. A meta-analysis was not conducted due to the heterogeneity of included data. Six additional barriers to immunization were identified: socioeconomic status, mother's education, geographic location, supply chain issues, father's education, number of children in the household, and media access.

Interpretation

The systematic review revealed the scarcity of available sex-stratified immunization data for Malagasy children. The evidence available was limited and heterogeneous, preventing researchers from conclusively confirming or denying differences in vaccine uptake based on sex. The low vaccination rates and additional barriers identified here indicate a need for increased focus on addressing the specific obstacles to vaccination in Madagascar. A more comprehensive assessment of sex-disaggregated vaccination status of Malagasy children and its relationship with such additional obstacles is recommended. Further investigation of potential differences in vaccination status will allow for the effective implementation of strategies to expand vaccine coverage in Madagascar equitably.

Funding and registration

AH, BT, FM, GN, and RR are supported by a grant from the Bill and Melinda Gates Foundation (grant number: OPP1205877). The review protocol is registered in the Prospective Register of Systematic Reviews (PROSPERO ID: CRD42021265000).

Zero- or missed-dose children in Nigeria: Contributing factors and interventions to overcome immunization service delivery challenges

'Zero-dose' refers to a person who does not receive a single dose of any vaccine in the routine national immunization schedule, while 'missed dose' refers to a person who does not complete the schedule. These peopleremain vulnerable to vaccine-preventable diseases, and are often already disadvantaged due to poverty, conflict, and lack of access to basic health services. Globally, more 22.7 million children are estimated to be zero- or missed-dose, of which an estimated 3.1 million (∼14 %) reside in Nigeria.We conducted a scoping review tosynthesize recent literature on risk factors and interventions for zero- and missed-dosechildren in Nigeria. Our search identified 127 papers, including research into risk factors only (n = 66); interventions only (n = 34); both risk factors and interventions (n = 18); and publications that made recommendations only (n = 9). The most frequently reported factors influencing childhood vaccine uptake were maternal factors (n = 77), particularly maternal education (n = 22) and access to ante- and perinatal care (n = 19); heterogeneity between different types of communities - including location, region, wealth, religion, population composition, and other challenges (n = 50); access to vaccination, i.e., proximity of facilities with vaccines and vaccinators (n = 37); and awareness about immunization - including safety, efficacy, importance, and schedules (n = 18).Literature assessing implementation of interventions was more scattered, and heavily skewed towards vaccination campaigns and polio eradication efforts. Major evidence gaps exist in how to deliver effective and sustainable routine childhood immunization. Overall, further work is needed to operationalise the learnings from these studies, e.g. through applying findings to Nigeria's next review of vaccination plans, and using this summary as a basis for further investigation and specific recommendations on effective interventions.

The Impact of COVID-19 Pandemic on Inequity in Routine Childhood Vaccination Coverage: A Systematic Review

Background: Routine childhood vaccination coverage rates fell in many countries during the COVID-19 pandemic, but the impact of inequity on coverage is unknown. Methods: We synthesised evidence on inequities in routine childhood vaccination coverage (PROSPERO, CRD 42021257431). Studies reporting empirical data on routine vaccination coverage in children 0–18 years old during the COVID-19 pandemic by equity stratifiers were systematically reviewed. Nine electronic databases were searched between 1 January 2020 and 18 January 2022. The risk of bias was assessed using the Newcastle-Ottawa Quality Assessment Tool for Cohort Studies. Overall, 91 of 1453 studies were selected for full paper review, and thirteen met the inclusion criteria. Results: The narrative synthesis found moderate evidence for inequity in reducing the vaccination coverage of children during COVID-19 lockdowns and moderately strong evidence for an increase in inequity compared with pre-pandemic months (before March 2020). Two studies reported higher rates of inequity among children aged less than one year, and one showed higher inequity rates in middle- compared with high-income countries. Conclusions: Evidence from a limited number of studies shows the effect of the pandemic on vaccine coverage inequity. Research from more countries is required to assess the global effect on inequity in coverage.

Vaccine equity in low and middle income countries: a systematic review and meta-analysis

BACKGROUND

Evidence to date has shown that inequality in health, and vaccination coverage in particular, can have ramifications to wider society. However, whilst individual studies have sought to characterise these heterogeneities in immunisation coverage at national level, few have taken a broad and quantitative view of the contributing factors to heterogeneity in immunisation coverage and impact, i.e. the number of cases, deaths, and disability-adjusted life years averted. This systematic review aims to highlight these geographic, demographic, and sociodemographic characteristics through a qualitative and quantitative approach, vital to prioritise and optimise vaccination policies.

METHODS

A systematic review of two databases (PubMed and Web of Science) was undertaken using search terms and keywords to identify studies examining factors on immunisation inequality and heterogeneity in vaccination coverage. Inclusion criteria were applied independently by two researchers. Studies including data on key characteristics of interest were further analysed through a meta-analysis to produce a pooled estimate of the risk ratio using a random effects model for that characteristic.

RESULTS

One hundred and eight studies were included in this review. We found that inequalities in wealth, education, and geographic access can affect vaccine impact and vaccination dropout. We estimated those living in rural areas were not significantly different in terms of full vaccination status compared to urban areas but noted considerable heterogeneity between countries. We found that females were 3% (95%CI[1%, 5%]) less likely to be fully vaccinated than males. Additionally, we estimated that children whose mothers had no formal education were 28% (95%CI[18%,47%]) less likely to be fully vaccinated than those whose mother had primary level, or above, education. Finally, we found that individuals in the poorest wealth quintile were 27% (95%CI [16%,37%]) less likely to be fully vaccinated than those in the richest.

CONCLUSIONS

We found a nuanced picture of inequality in vaccination coverage and access with wealth disparity dominating, and likely driving, other disparities. This review highlights the complex landscape of inequity and further need to design vaccination strategies targeting missed subgroups to improve and recover vaccination coverage following the COVID-19 pandemic.

TRIAL REGISTRATION

Prospero, CRD42021261927.

Tetanus seroprotection among children in the Democratic Republic of the Congo, 2013-2014

BACKGROUND

Tetanus is a potentially fatal disease that is preventable through vaccination. While the Democratic Republic of the Congo (DRC) has continued to improve implementing routine vaccination activities throughout the country, they have struggled to maintain high childhood vaccine coverage. This study aims to examine the seroprevalence of tetanus in children 6 to 59 months to identify areas for intervention and improvement of vaccination coverage.

METHODS

In collaboration with the 2013-2014 Demographic and Health Survey, we assessed the seroprevalence of tetanus antibodies among children in the DRC. Dried blood spot samples collected from children 6-59 months of age were processed using a prototype DYNEX Multiplier® chemiluminescent automated immunoassay instrument with a multiplex measles, mumps, rubella, varicella and tetanus assay. Multivariable logistic regression was used to determine factors associated with tetanus vaccination and seroprotection.

RESULTS

Overall, 36.1% of children 6-59 months of age reported receiving at least 1 dose of tetanus vaccine while 28.7% reported receiving 3 doses; tetanus seroprotection was 40%. Increasing age in children was associated with decreased tetanus seroprotection, but increased number tetanus vaccinations received. Factors related to increased tetanus seroprotection included number of children in the household, wealth index of the family, urban residence compared to rural, level of maternal education, and province and geography.

CONCLUSIONS

Our findings in this nationally representative sample indicate that serology biomarkers may help identify children who are not fully immunized to tetanus more accurately than reported vaccination. While children may be captured for routine immunization activities, as children age, decreasing seroprevalence may indicate additional need to bolster routine vaccination activities and documentation of vaccination in school aged children. Additionally, the study highlights gaps in rural residential areas and vaccination coverage based on maternal education, indicating that policies targeting maternal education and awareness could improve the coverage and seroprevalence of tetanus antibodies in the DRC.

Ethnic disparities in immunisation: analyses of zero-dose prevalence in 64 countries

BACKGROUND

The Sustainable Development Goals (SDGs) recommend stratification of health indicators by ethnic group, yet there are few studies that have assessed if there are ethnic disparities in childhood immunisation in low-income and middle-income countries (LMICs).

METHODS

We identified 64 LMICs with standardised national surveys carried out since 2010, which provided information on ethnicity or a proxy variable and on vaccine coverage; 339 ethnic groups were identified after excluding those with fewer than 50 children in the sample and countries with a single ethnic group. Lack of vaccination with diphtheria-pertussis-tetanus vaccine-a proxy for no access to routine vaccination or 'zero-dose' status-was the outcome of interest. Differences among ethnic groups were assessed using a χ2 test for heterogeneity. Additional analyses controlled for household wealth, maternal education and urban-rural residence.

FINDINGS

The median gap between the highest and lowest zero-dose prevalence ethnic groups in all countries was equal to 10 percentage points (pp) (IQR 4-22), and the median ratio was 3.3 (IQR 1.8-6.7). In 35 of the 64 countries, there was significant heterogeneity in zero-dose prevalence among the ethnic groups. In most countries, adjustment for wealth, education and residence made little difference to the ethnic gaps, but in four countries (Angola, Benin, Nigeria and Philippines), the high-low ethnic gap decreased by over 15 pp after adjustment. Children belonging to a majority group had 29% lower prevalence of zero-dose compared with the rest of the sample.

INTERPRETATION

Statistically significant ethnic disparities in child immunisation were present in over half of the countries studied. Such inequalities have been seldom described in the published literature. Regular analyses of ethnic disparities are essential for monitoring trends, targeting resources and assessing the impact of health interventions to ensure zero-dose children are not left behind in the SDG era.

Wealth and Education Inequities in Maternal and Child Health Services Utilization in Rural Ethiopia

As part of the 2030 maternal and child health targets, Ethiopia strives for universal and equitable use of health services. We aimed to examine the association between household wealth, maternal education, and the interplay between these in utilization of maternal and child health services. Data emanating from the evaluation of the Optimizing of Health Extension Program intervention. Women in the reproductive age of 15 to 49 years and children aged 12-23 months were included in the study. We used logistic regression with marginal effects to examine the association between household wealth, women's educational level, four or more antenatal care visits, skilled assistance at delivery, and full immunization of children. Further, we analyzed the interactions between household wealth and education on these outcomes. Household wealth was positively associated with skilled assistance at delivery and full child immunization. Women's education had a positive association only with skilled assistance at delivery. Educated women had skilled attendance at delivery, especially in the better-off households. Our results show the importance of poverty alleviation and girls' education for universal health coverage.

Trends, projection and inequalities in full immunization coverage in Ethiopia: in the period 2000-2019

BACKGROUND

Immunization is among the most cost-effective health interventions to improve child survival. However, many countries in sub-Saharan Africa failed to achieve their national and international coverage targets repeatedly. The present study investigated trends of coverage and inequalities in coverage in Ethiopia.

METHODS

This study used data from five rounds of the Demographic and Health Surveys conducted in Ethiopia in 2000, 2005, 2011, 2016, and 2019. The surveys used a multistage cluster sampling procedure to obtain a nationally and sub-nationally representative data. The outcome variables included in the study were full immunization coverage and inequality. The World Health Organization's Health Equity Assessment Toolkit was used to conduct the inequality analysis. Projections for 2025 were based on smoothed averages generated using the demographic and health survey data from 2000 to 2019.

RESULTS

The full (basic) immunization coverage in Ethiopia has increased steadily from 14.3% in 2000 to 44.1% in 2019. Based on the average past performance, the immunization coverage is projected to reach 53.6% by 2025, which will be short of the 75% national full (basic) immunization coverage target for the year 2025. Mothers with higher levels of education are more likely to get their children all basic vaccinations than those with lower levels of education. Similarly, the inequality gaps due to wealth and residency are significant; where children in the lowest wealth strata and those living in rural areas remained disadvantaged.

CONCLUSION

Despite a steady increase in immunization coverage in the past two decades the country is yet to achieve its immunization target. Thus, more efforts are needed to achieve the current and future national immunization targets. A more focused intervention targeting the disadvantaged groups could be an effective strategy to achieve coverage and minimize the inequality gaps in immunization.

Determinants of immunisation dropout among children under the age of 2 in Zambézia province, Mozambique: a community-based participatory research study using Photovoice

OBJECTIVE

Immunisations are highly impactful, cost-effective public health interventions. However, substantial gaps in complete vaccination coverage persist. We aimed to describe caregivers' immunisation experiences and identify determinants of vaccine dropout.

DESIGN

We used a community-based participatory research approach employing Photovoice, SMS (short messaging service) exchanges and in-depth interviews. A team-based approach was used for thematic analysis. The Increasing Vaccination Model guided the analysis and identification of vaccination facilitators and barriers.

SETTING

This study was conducted in Zambézia province, Mozambique, in Namarroi and Gilé districts, where roughly 19% of children under 2 start but do not complete the recommended vaccination schedule.

PARTICIPANTS

Participants were identified through health facility vaccination records and included caregivers of children aged 25-34 months who were fully vaccinated (n=10) and partially vaccinated (n=22). We also collected data from 12 health workers responsible for delivering immunisations at the selected health facilities.

RESULTS

Four main patterns of barriers leading to dropout emerged: (1) social norms and limited family support place the immunisation burden on mothers; (2) perceived poor quality of health services reduces caregivers' trust in vaccination services; (3) concern about side effects causes vaccine hesitancy; and (4) caregivers hesitate to seek and advocate for vaccination due to power imbalances with health workers. COVID-19 created additional barriers related to social distancing, mask requirements, supply chain challenges and disrupted outreach services. For most caregivers, dropout becomes increasingly likely with compounding barriers. Caregivers of fully-vaccinated children noted facilitators, including accompaniment to health facilities or assistance caring for other children, which enabled them to complete vaccination.

CONCLUSIONS

Overcoming immunisation barriers requires strengthening health systems, including improving logistics to avert vaccine stockouts and building health worker capacity, including empathic communication with caregivers. Consistent and reliable immunisation outreach services could address access challenges and improve immunisation uptake, particularly in distant communities.

Building evidence for improving vaccine adoption and uptake of childhood vaccinations in low- and middle-income countries: a systematic review

Vaccine coverage for children is an important indicator of the performance of national health and immunization systems. Most of the existing literature has targeted mothers’ low educational level, living in underserved districts and/or remote rural areas and economic poverty that are correlated with low immunization coverage but the supply- and demand-side constraints to immunization in low- and middle- income countries (LMICs) are not well understood. The reliability of claimed administrative immunization coverage in these contexts is questionable. To address these barriers within the present Expanded Programme on Immunization (EPI), the difficulties related to inadequate vaccination uptake must be addressed in more depth. Building on already produced literature, this study aims to determine the extent of immunization coverage among children in LMICs, as well as to fill in the gaps in awareness about system-level obstacles that currently hinder the effective delivery and uptake of immunization services through EPI. By two reviewers, a literature search using PubMed and Google Scholar along with targeted grey literature was conducted on the 2nd of June 2021 by following PRISMA guidelines. The search techniques for electronic databases used both Medical Subject Headings (Mesh) and free-text words were tailored to each database's specific needs using a controlled vocabulary that was limited to the English language from 2000 and 2020. Of the 689 records, eleven articles were included in this review meeting the inclusion criteria. In total, five articles related to vaccination coverage, four studies on components of the routine immunization system, one article on the implementation of new and under-utilized vaccines and one were on vaccines financing. We evaluated the quality of the included studies and extracted into tables created by one investigator and double-checked by another. Review findings suggest that specific strategies to reduce inequality may be required. Vaccine procurement and pricing strategies, as well as vaccine customization to meet the needs of LMICs, are all critical components in strengthening immunization systems. Our findings could be used to establish practical strategies for countries and development partners to address coverage gaps and improve vaccination system effectiveness.

Inequalities in full vaccination coverage based on maternal education and wealth quintiles among children aged 12-23 months: further analysis of national cross-sectional surveys of six South Asian countries

OBJECTIVE

This study was conducted to compare full vaccination coverage and its inequalities (by maternal education and household wealth quintile).

DESIGN

This further analysis was based on the data from national-level cross-sectional Demographic and Health Survey (DHS) from six countries in South Asia.

SETTING

We used most recent DHS data from six South Asian countries: Nepal, India, Pakistan, Bangladesh, Afghanistan and the Maldives. The sample size of children aged 12-23 months ranged from 6697 in the Maldives to 628 900 in India.

PRIMARY AND SECONDARY OUTCOME MEASURES

To measure absolute and relative inequalities of vaccination coverage, we used regression-based inequality measures, slope index of inequality (SII) and the relative index of inequality (RII), respectively, by maternal education and wealth quintile.

RESULTS

Full vaccination coverage was the highest in Bangladesh (84%) and the lowest in Afghanistan (46%), with an average of 61.5% for six countries. Pakistan had the largest inequalities in coverage both by maternal education (SII: -50.0, RII: 0.4) and household wealth quintile (SII: -47.1, RII: 0.5). Absolute inequalities were larger by maternal education compared with wealth quintile in four of the six countries. The relative index of inequality by maternal education was lower in Pakistan (0.5) and Afghanistan (0.5) compared with Nepal (0.7), India (0.7) and Bangladesh (0.7) compared with rest of the countries. By wealth quintiles, RII was lower in Pakistan (0.5) and Afghanistan (0.6) and higher in Nepal (0.9) and Maldives (0.9).

CONCLUSIONS

The full vaccination coverage in 12-23 months old children was below 85% in all six countries. Inequalities by maternal education were more profound than household wealth-based inequalities in four of six countries studied, supporting the benefits of maternal education to improve child health outcome.

Decomposing socio-economic inequality in vaccination coverage among Pakistani children: A population-based cross-sectional study

There is scarce knowledge about factors contributing to underlying inequalities in vaccination coverage among Pakistani children. Therefore, the main objective of this study is to measure and decompose socioeconomic inequalities in childhood vaccination coverage. Pakistan Demographic and Health Survey, version 2017-18, data were used for analysis. Bivariate association was checked through Chi-square test and concentration curve (CC) and concentration index (CI) were used to assess the existence and nature of inequality. Finally, decomposition analysis was performed to measure the contribution of different factors to the observed inequality. Our findings suggested that vaccination coverage is more concentrated among children of educated mothers (CI = 0.296) and decomposition results suggest that a substantial proportion of the inequality is explained by maternal education, wealth status, paternal education and improved sanitation (34%, 19%, 14% and 21% respectively). Also, differences are observed between regions regarding vaccination coverage. There is need of female-targeted interventions to increase maternal role in the society through better education and decision-making autonomy. Also, the policies to improve the household's wealth status should be considered.

Examining community pharmacists' intention to provide pharmacist-driven vaccination services: A structural equation modelling

BACKGROUND

The evidence of pharmacists' current involvement in vaccination services in low- and middle-income countries (LMICs) is uncertain. This study would be a first step to develop vaccination services by investigating community pharmacists' intention to be involved in PDV services not just during COVID-19 pandemic but also during standard service provision in Turkey which can be taken as an example across LMICs.

OBJECTIVE

Considering the efforts to empower community pharmacists in service provision, the goal of the present study was to develop a structural equation model to explain the "Pharmacist-Driven Vaccination Service Intention Model (PDV-SIM)" by using the theory of planned behavior (TPB).

METHODS

Based on the constructs of TPB, a measurement tool was developed. Sub-factors of PDV service intention was determined by conducting exploratory factor analysis (EFA). In the second step, confirmatory factor analysis (CFA) was conducted to prove the theoretical structure of the tool. Finally, a model explaining the relationship between observed variables, latent constructs from TPB was developed by SEM analysis.

RESULTS

In the proposed PDV-SIM, patient related attitude toward PDV services, attitude toward negative consequences of PDV services, and subjective norm about PDV services had an impact on the behavioral intention of community pharmacists. Nevertheless, professional development attitude toward PDV services and perceived behavioral control were not evaluated as determinants of the behavioral intention.

CONCLUSION

Results of this study revealed that TPB is appropriate for modelling PDV service intention of community pharmacists. This model can be utilized as a guide to potential pharmacy regulatory bodies and policy makers in their efforts to enable community pharmacists as vaccinators across LMICs.

Demographic and health surveys showed widening trends in polio immunisation inequalities in Guinea

AIM

This study examined trends in absolute and relative socio-economic, gender and geographical inequalities in the coverage of polio immunisation in Guinea, West Africa, from 1999 to 2016.

METHODS

Data from the 1999, 2005 and 2012 Guinea Demographic and Health Survey and the 2016 Guinea Multiple Indicator Cluster Survey were analysed using the World Health Organization's health equity assessment toolkit. We disaggregated polio immunisation coverage using five equity stratifiers: household economic status, maternal educational level, place of residence, child's gender and region. The four summary measures used were the difference, ratio, population attributable risk and population attributable fraction. A 95% confidence interval (CI) was constructed around point estimates to measure statistical significance.

RESULTS

A total of 4778 1-year-old children were included. Polio immunisation coverage in 1999, 2005, 2012 and 2016 were 43.4%, 50.7%, 51.2% and 38.6%, respectively. Socio-economic and geographical inequalities in polio immunisation favoured children with educated mothers who came from richer families living in urban areas. There were also differences in the eight regions over the 1999-2016 study period.

CONCLUSION

Targeting children from disadvantaged subgroups must be prioritised to ensure equitable immunisation services that help to eradicate polio in Guinea.

How can the public health impact of vaccination be estimated?

Background

Deaths due to vaccine preventable diseases cause a notable proportion of mortality worldwide. To quantify the importance of vaccination, it is necessary to estimate the burden averted through vaccination. The Vaccine Impact Modelling Consortium (VIMC) was established to estimate the health impact of vaccination.

Methods

We describe the methods implemented by the VIMC to estimate impact by calendar year, birth year and year of vaccination (YoV). The calendar and birth year methods estimate impact in a particular year and over the lifetime of a particular birth cohort, respectively. The YoV method estimates the impact of a particular year’s vaccination activities through the use of impact ratios which have no stratification and stratification by activity type and/or birth cohort. Furthermore, we detail an impact extrapolation (IE) method for use between coverage scenarios. We compare the methods, focusing on YoV for hepatitis B, measles and yellow fever.

Results

We find that the YoV methods estimate similar impact with routine vaccinations but have greater yearly variation when campaigns occur with the birth cohort stratification. The IE performs well for the YoV methods, providing a time-efficient mechanism for updates to impact estimates.

Conclusions

These methods provide a robust set of approaches to quantify vaccination impact; however it is vital that the area of impact estimation continues to develop in order to capture the full effect of immunisation.

Child Vaccination Coverage, Trends and Predictors in Eastern Ethiopia: Implication for Sustainable Development Goals

BACKGROUND

Every year, immunization prevents about 4-5 million child fatalities from vaccine preventable morbidities. Conversely, in Ethiopia, achieving full coverage of vaccination has continued to be challenging. Socio-demographic, caregivers and child related factors determine vaccination coverage. Therefore, this study aimed to find out recent coverage, trends in coverage, and its predictors in eastern Ethiopia.

METHODS

A population-based longitudinal study design was conducted among 14,246 children aged 12-24 months from 2017 to 2021 in Kersa Health and Demographic Surveillance System site (KHDSS). The data were collected from caregivers of the child by face to face interview. Multinomial logistic regressions were used to identify predictors of vaccination. The association between vaccination coverage and its predictors was presented by adjusted odds ratio with 95% confidence interval. A p-value of <0.05 was used to establish statistical significance.

RESULTS

From the 14,198 included children, only 39% of children were fully vaccinated, with highest proportion in 2020 (45%) and lowest proportion in 2019 (32%). In comparison to fully vaccinated, being partially vaccinated was positively associated with older maternal age, rural residence, unemployment, rich wealth index, no antenatal care, facility delivery, and birth order whereas negatively associated with semi-urban residence. In compared to fully vaccinated, being not vaccinated was positively associated with older maternal age, rural residence, maternal education, unemployment, and no antenatal care whereas negatively associated with semi-urban residence, poor wealth index, multipara, grand multipara, and facility delivery.

CONCLUSION

Less than two-fifths of children aged 12 to 24 months were fully vaccinated. Socio-demographic factors and maternity care utilization were found to be predictors of vaccination coverage. Therefore, strategies that emphasize women's empowerment in terms of education, economy, and employment status, and enhancing maternal healthcare utilization may improve vaccination coverage.

Cross-cutting lessons from the Decision-Maker Led Implementation Research initiative

BACKGROUND

Almost 20 million children under one year of age did not receive basic vaccines in 2019, and most of these children lived in low- and middle-income countries. Implementation research has been recognized as an emerging area that is critical to strengthen the implementation of interventions proven to be effective. As a component of strengthening implementation, WHO has called for greater embedding of research within decision-making processes. One strategy to facilitate the embedding of research is to engage decision-makers as Principal Investigators of the research. Since 2015, the Alliance for Health Policy and Systems Research within the WHO and the United Nations Children's Fund have supported decision-maker led research by partnering with Gavi, the Vaccine Alliance, in an initiative called "Decision-Maker Led Implementation Research". This synthesis paper describes the cross-cutting lessons from the initiative to further understand and develop future use of the decision-maker led strategy.

METHODS

This study used qualitative methods of data collection, including a document review and in-depth interviews with decision-makers and researchers engaged in the initiative. Document extraction and thematic content analysis were applied. The individual project was the unit of analysis and the results were summarized across projects.

RESULTS

Research teams from 11 of the 14 projects participated in this study, for an overall response rate of 78.6%. Most projects were carried out in countries in Africa and conducted at the sub-state or sub-district level. Seven enablers and five barriers to the process of conducting the studies or bringing about changes were identified. Key enablers were the relevance, acceptability, and integration of the research, while key barriers included unclear results, limited planning and support, and the limited role of a single study in informing changes to strengthen implementation.

CONCLUSIONS

Decision-maker led research is a promising strategy to facilitate the embedding of research into decision-making processes and contribute to greater use of research to strengthen implementation of proven-effective interventions, such as immunization. We identified several lessons for consideration in the future design and use of the decision-maker led strategy.

Supply and delivery of vaccines for global health

Vaccines developed in high-income countries have been enormously successful in reducing the global burden of infectious diseases, saving perhaps 2.5 million lives per year, but even for successful cases, like the rotavirus vaccine, global implementation may take a decade or more. For unincentivized vaccines, the delays are even more profound, as both the supply of a vaccine from developing country manufacturers and vaccine demand from countries with the high disease burdens have to be generated in order for impact to be manifest. A number of poverty-associated infectious diseases, whose burden is greatest in low-income and middle-income countries, would benefit from appropriate levels of support for vaccine development such as Group A Streptococcus, invasive non-typhoid salmonella, schistosomiasis, shigella, to name a few. With COVID-19 vaccines we will hopefully be able to provide novel vaccine technology to all countries through a unique collaborative effort, the COVAX facility, led by the World Health Organization (WHO), Gavi, and the Coalition for Epidemic Preparedness Innovations (CEPI). Whether this effort can deliver vaccine to all its participating countries remains to be seen, but this ambitious effort to develop, manufacture, distribute, and vaccinate 60-80% of the world's population will hopefully be a lasting legacy of COVID-19.

Vaccination coverage in children up to 2 years old, receiving financial support from the Family Income Transfer Program, Brazil

OBJECTIVE

To assess vaccination coverage, based on the National Immunization Program schedule, among children receiving financial support from the Family Income Transfer Program, Brazil, according to the family socioeconomic status and maternal characteristics.

METHODS

3,242 children under 12 months old were assessed between August/2018 and April/2019, of whom 3,008 were reassessed between September/2019 and January/2020. The analyses were performed using multilevel models (level 3, Federative Unit; level 2, municipality; level 1, children).

RESULTS

Vaccination coverage was 2.5 fold higher in the first follow-up (61.0% - 95% CI 59.3;62.6%), compared to the second follow-up (24.8% - 95% CI 22.8;25.9%) (p<0.001). In the first follow-up, coverage was higher in the richest quintile (67.9%) and in children whose mothers had ≥9 years of schooling (63.3%). In the second follow-up, there were no differences. The highest coverage occurred between 0.5-2.5 (93.5%) and 12.5-15.5 months (34.4%), respectively, first and second follow-ups.

CONCLUSION

Low coverage was found, both in the first and second year of life.

The effect of bearing and rearing a child on blood pressure: a nationally representative instrumental variable analysis of 444611 mothers in India

BACKGROUND

At the individual level, it is well known that pregnancies have a short-term effect on a woman's cardiovascular system and blood pressure. The long-term effect of having children on maternal blood pressure, however, is unknown. We thus estimated the causal effect of having children on blood pressure among mothers in India, a country with a history of high fertility rates.

METHODS

We used nationally representative cross-sectional data from the 2015-16 India National Family and Health Survey (NFHS-4). The study population comprised 444 611 mothers aged 15-49 years. We used the sex of the first-born child as an instrumental variable (IV) for the total number of a woman's children. We estimated the effect of an additional child on systolic and diastolic blood pressure in IV (two-stage least squares) regressions. In additional analyses, we stratified the IV regressions by time since a mother last gave birth. Furthermore, we repeated our analyses using mothers' husbands and partners as the regression sample.

RESULTS

On average, mothers had 2.7 children [standard deviation (SD): 1.5], a systolic blood pressure of 116.4 mmHg (SD: 14.4) and diastolic blood pressure of 78.5 mmHg (SD: 9.4). One in seven mothers was hypertensive. In conventional ordinary least squares regression, each child was associated with 0.42 mmHg lower systolic [95% confidence interval (CI): -0.46 to -0.39, P < 0.001] and 0.13 mmHg lower diastolic (95% CI: -0.15 to -0.11, P < 0.001) blood pressure. In the IV regressions, each child decreased a mother's systolic blood pressure by an average of 1.00 mmHg (95% CI: -1.26 to -0.74, P < 0.001) and diastolic blood pressure by an average of 0.35 mmHg (95% CI: -0.52 to -0.17, P < 0.001). These decreases were sustained over more than a decade after childbirth, with effect sizes slightly declining as the time since last birth increased. Having children did not influence blood pressure in men.

CONCLUSIONS

Bearing and rearing a child decreases blood pressure among mothers in India.

Maternal healthcare utilsation and complete childhood vaccination in sub-Saharan Africa: a cross-sectional study of 29 nationally representative surveys

OBJECTIVE

The objective of the study was to examine the association between maternal healthcare utilisation and complete childhood vaccination in sub-Saharan Africa.

DESIGN

Our study was a cross-sectional study that used pooled data from 29 countries in sub-Saharan Africa.

PARTICIPANTS

A total of 60 964 mothers of children aged 11-23 months were included in the study.

OUTCOME VARIABLES

The main outcome variable was complete childhood vaccination. The explanatory variables were number of antenatal care (ANC) visits, assistance during delivery and postnatal care (PNC).

RESULTS

The average prevalence of complete childhood vaccination was 85.6%, ranging from 67.0% in Ethiopia to 98.5% in Namibia. Our adjusted model, children whose mothers had a maximum of three ANC visits were 56% less likely to have complete vaccination, compared with those who had at least four ANC visits (adjusted OR (aOR)=0.44, 95% CI 0.42 to 0.46). Children whose mothers were assisted by traditional birth attendant/other (aOR=0.43, 95% CI 0.41 to 0.56) had lower odds of complete vaccination. The odds of complete vaccination were lower among children whose mothers did not attend PNC clinics (aOR=0.26, 95% CI 0.24 to 0.29) as against those whose mothers attended.

CONCLUSION

The study found significant variations in complete childhood vaccination across countries in sub-Saharan Africa. Maternal healthcare utilisation (ANC visits, skilled birth delivery, PNC attendance) had significant association with complete childhood vaccination. These findings suggest that programmes, interventions and strategies aimed at improving vaccination should incorporate interventions that can enhance maternal healthcare utilisation. Such interventions can include education and sensitisation, reducing cost of maternal healthcare and encouraging male involvement in maternal healthcare service utilisation.

Change in full immunization inequalities in Indian children 12-23 months: an analysis of household survey data

BACKGROUND

India has made substantial progress in improving child health in recent years. However, the country continues to account for a large number of vaccine preventable child deaths. We estimated wealth-related full immunization inequalities in India. We also calculated the degree to which predisposing, reinforcing, and enabling factors contribute to these inequalities.

METHODS

We used data from the two rounds of a large nationally representative survey done in all states in India in 2005-06 (n = 9582) and 2015-16 (n = 49,284). Full immunization status was defined as three doses of diphtheria-tetanus-pertussis vaccine, three doses of polio vaccine, one dose of Bacillus Calmette-Guérin vaccine, and one dose of measles vaccine in children 12-23 months. We compared full immunization coverage by wealth quintiles using descriptive statistics. We calculated concentration indices for full immunization coverage at the national and state levels. Using predisposing, reinforcing, and enabling factors associated with full immunization status identified from the literature, we applied a generalized linear model (GLM) framework with a binomial distribution and an identity link to decompose the concentration index.

RESULTS

National full immunization coverage increased from 43.65% in 2005-06 to 62.46% in 2015-16. Overall, full immunization coverage in both 2005-06 and 2015-16 in all states was lowest in children from poorer households and improved with increasing socioeconomic status. The national concentration index decreased from 0.36 to 0.13 between the two study periods, indicating a reduction in poor-rich inequality. Similar reductions were observed for most states, except in states where inequalities were already minimal (i.e., Tamil Nadu) and in some northeastern states (i.e., Meghalaya and Manipur). In 2005-06, the contributors to wealth-related full immunization inequality were antenatal care, maternal education, and socioeconomic status. The same factors contributed to full immunization inequality in 2015-16 in addition to difficulty reaching a health facility.

CONCLUSIONS

Immunization coverage and wealth-related equality have improved nationally and in most states over the last decade in India. Targeted, context-specific interventions could help address overall wealth-related full immunization inequalities. Intensified government efforts could help in this regard, particularly in high-focus states where child mortality remains high.

Missed childhood immunizations during the COVID-19 pandemic in Brazil: Analyses of routine statistics and of a national household survey

INTRODUCTION

There is widespread concern that disruption to health services during the COVID-19 pandemic has led to declines in immunization coverage among young children, but there is limited information on the magnitude of such impact. High immunization coverage is essential for reducing the risk of vaccine preventable diseases.

METHODS

We used data from two nationwide sources covering the whole of Brazil. Data from the Information System of the National Immunization Program (SIPNI) on the monthly number of vaccine doses administered to young children were analyzed. The second source was a survey in 133 large cities in the 27 states in the country, carried out from August 24-27. Respondents answered a question on whether children under the age of three years had missed any scheduled vaccinations during the pandemic, and available vaccination cards were photographed for later examination.

RESULTS

SIPNI data showed that, relative to January and February 2020, there was a decline of about 20% in vaccines administered to children aged two months or older during March and April, when social distancing was at the highest level in the country. After May, vaccination levels returned to pre-pandemic values. Survey data, based on the interviews and on examination of the vaccine cards, showed that 19.0% (95% CI 17.0;21.1%) and 20.6% (95% CI 19.0;23.1%) of children, respectively, had missed immunizations. Missed doses were most common in the North (Amazon) region and least common in the South and Southeast, and also more common among children from poor than from wealthy families.

INTERPRETATION

Our results show that the pandemic was associated with a reduction of about 20% in child vaccinations, but this was reverted in recent months. Children from poor families and from the least developed regions of the country were most affected. There is an urgent need to booster immunization activities in the country to compensate for missed doses, and to reduce geographic and socioeconomic inequalities.

Persistent Socioeconomic Inequalities in Measles Vaccine Uptake in Ethiopia in the Period 2005 to 2016

OBJECTIVE

This study aims to quantify socioeconomic inequalities-and the factors contributing to these inequalities-in measles vaccine uptake among children aged 12 to 23 months in Ethiopia between 2005 and 2016.

METHODS

Inequalities in measles vaccine uptake were investigated based on data from the Ethiopian Demographic and Health Surveys conducted in 2005, 2011, and 2016. Concentration curves and concentration indices were used to measure the degree of inequality, and decomposition analysis was used to identify factors contributing to these inequalities.

RESULTS

The overall level of national measles vaccine uptake in Ethiopia exhibited an increasing trend between 2005 and 2016. As indicated by the concentration index of measles vaccine uptake, however, which was estimated at 0.202 (P < .01) in 2005, 0.226 (P < .01) in 2011, and 0.223 (P < .01) in 2016, measles vaccine uptake became consistently more concentrated among children from more affluent households. The dominance test of the concentration curve further confirmed the persistence of inequalities in measles vaccine uptake over time. Various factors-including maternal educational level, antenatal care use, institutional delivery, and exposure to media-were identified as the most important contributors to the inequalities.

CONCLUSIONS

Although the national measles vaccine uptake showed improvement between 2005 and 2016, socioeconomic inequalities in the uptake persisted over time. Efforts to improve the national immunization coverage should be accompanied by appropriate measures to address the inequalities.

Institutional mistrust and child vaccination coverage in Africa

INTRODUCTION

Despite considerable improvements in vaccination coverage over the last decade, half of the world's unvaccinated and undervaccinated children are located in Africa. The role of institutional trust in explaining vaccination gaps has been highlighted in several qualitative reports but so far has only been quantified in a small number of high-income countries.

METHODS

We matched information on child vaccination status from the Demographic Health Surveys with information on institutional trust from the Afrobarometer surveys at the subnational level. A total of 166 953 children from 41 surveys administered in 22 African countries covering 216 subnational regions were used. Based on a principal component analysis, we constructed an institutional mistrust index that combined the level of mistrust in the head of state, parliament, electoral system, courts and local government. Associations between institutional mistrust and child vaccination uptake were assessed with multivariable fixed effects logistic regressions that controlled for time-invariant subnational region characteristics and various child, caregiver, household and community characteristics.

RESULTS

A 1 SD increase in the institutional mistrust index was associated with a 10% (95% CI of ORs: 1.03 to 1.18) increase in the likelihood that a child had not received any of eight basic vaccines and with a 6% decrease in the likelihood a child had received all of the basic vaccines (95% CI: 0.92 to 0.97). Institutional mistrust was negatively associated with the likelihood that a child had received each of the eight basic vaccinations (p<0.05).

CONCLUSIONS

Child vaccination rates in Africa are considerably lower in areas in which the local population displays high levels of mistrust towards local authorities. Institutional mistrust is an important dimension of vaccine hesitancy, considered as one of the most important threats to global health. Empowering local authorities with resources and communication strategies to address institutional mistrust may be needed to close the remaining vaccination gaps in Africa.

Full immunization coverage and associated factors among children age 12-23 months in Ethiopia: systematic review and meta-analysis of observational studies

Background: Millions of children in developing countries remained unvaccinated and under-vaccinated. This study was aimed to determine the pooled full vaccination coverage and associated factors in Ethiopia.Methods: This review and meta-analysis were included observational studies conducted from 2013 to 2020. The international online databases as well as gray literatures were retrieved from April 15 to 30/2020. The quality of each study was assessed using the Newcastle-Ottawa Quality Assessment Scale (NOS). Data were extracted using Microsoft excel 2016 and analyzed using STATA 11.0 statistical software. Heterogeneity among studies was assessed using the Cochran Q statistics and I² test. The pooled effect sizes were determined using pooled proportion for the full vaccination coverage and odds ratios for the associated factors with the corresponding 95% confidence interval.Result: Sixteen studies with 8305 children aged 12-23 months were included. The overall pooled full vaccination coverage was 65% (95% CI: 56%-74%). Institutional delivery (OR: 2.12, 95% CI: 1.78-2.52), travel to vaccination site for <2 hours (OR: 2.43, 95%CI: 1.97-3.00), received at least one antenatal (ANC) visit (OR: 3.2, 95%CI: 2.46-4.1), good maternal knowledge of immunization (OR: 3.63, 95%CI: 2.82-4.67), being informed on immunization schedule (OR: 2.54, 95%CI: 2.02-3.2), living in urban areas (OR: 2, 95% CI: 1.54-2.6), and a household visit by health-care providers during the postnatal period (OR: 2.23, 95%CI: 1.22-4.09) were the independent predictors of full immunization coverage among children age 12-23 months.Conclusion: The study showed that the pooled full immunization coverage is still far from the national target (90%). Therefore, the government should strengthen both the outreach and facility-based immunization services.

The Burden of Invasive Vaccine-Preventable Diseases in Adults in the Middle East and North Africa (MENA) Region

Implementing vaccination programmes at the national level is key to managing vaccine-preventable diseases (VPDs) in the overall population. Although paediatric immunization programmes have significantly reduced the burden of VPD, disease burden in adults still poses a substantial challenge, particularly in low- and middle-income countries such as those within the Middle East and North Africa (MENA) region. Invasive bacterial diseases (IBDs) are an important public health concern within this region, although vaccines are available to prevent the three most common causative organisms associated with IBD: Neisseria meningitidis (NM), Streptococcus pneumoniae (SP), and Haemophilus influenzae (HI). For this review, three separate PubMed searches were used to identify English-language publications describing the epidemiology of NM, SP, and HI in adults within the MENA region. Of the 161 total publications retrieved among all 3 literature searches, 39 were included in this review (NM: 8 publications; SP: 27 publications; HI: 4 publications). Publications describing epidemiology in paediatric or overall populations were excluded. Overall, these studies generally observed a high burden of IBD among adults in this region. Although NM, SP, and HI are communicable diseases in several countries, the surveillance systems in the MENA region are largely inadequate, resulting in poor responses to outbreaks and hindering improvement in outcomes of communicable diseases. Improving IBD surveillance would provide necessary estimates of disease burden, resulting in better vaccination strategies and improved outcomes. In conclusion, the present review provides a summary of the available information on the epidemiology of vaccine-preventable IBD in adults within the MENA region and highlights the need for increased disease surveillance and preventive strategies in these countries.

Drivers of hesitancy towards recommended childhood vaccines in African settings: a scoping review of literature from Kenya, Malawi and Ethiopia

INTRODUCTION

There is a dearth of literature on vaccine hesitancy in Africa. In this study, we aimed to explore the drivers of hesitancy toward recommended childhood vaccines in Kenya, Malawi, and Ethiopia.

METHODS

A scoping review methodology was used as this evidence synthesis approach is suitable for mapping existing literature and identifying knowledge gaps. For this study, we systematically searched four electronic databases for published and unpublished literature from the three African countries. The methodological framework that was used is in line with Arksey and O'Malley's recommendations as modified by Levac.

RESULTS

A total of 23 publications met the inclusion criteria and were included in the study. Majority of the studies were published after 2012. In these three African countries, hesitancy toward recommended childhood vaccines is driven by a mix of caregiver-related factors, health systems-related factors as well as the influence of community context.

CONCLUSION

This study demonstrated that vaccine hesitancy in Kenya, Malawi, and Ethiopia is a complex phenomenon that is driven by multiple interrelated and interconnected factors.

Zero-dose children and the immunisation cascade: Understanding immunisation pathways in low and middle-income countries

INTRODUCTION

Zero-dose prevalence refers to children who failed to receive any routine vaccination. Little is known about the "immunisation cascade" in low- and middle-income countries (LMICs), defined as how children move from zero dose to full immunisation.

METHODS

Using data from national surveys carried out in 92 LMICs since 2010 and focusing on the four basic vaccines delivered in infancy (BCG, polio, DPT and MCV), we describe zero-dose prevalence and the immunisation cascade in children aged 12 to 23 months. We also describe the most frequent combinations of vaccines (or co-coverage) among children who are partially immunized. Analyses are stratified by country income groups, household wealth quintiles derived from asset indices, sex of the child and area of residence. Results were pooled across countries using child populations as weights.

RESULTS

In the 92 countries, 7.7% were in the zero-dose group, and 3.3%, 3.4% and 14.6% received one, two or three vaccines, respectively; 70.9% received the four types and 59.9% of the total were fully immunised with all doses of the four vaccines. Three quarters (76.8%) of children who received the first vaccine received all four types. Among children with a single vaccine, polio was the most common in low- and lower-middle income countries, and BCG in upper-middle income countries. There were sharp inequalities according to household wealth, with zero-dose prevalence ranging from 12.5% in the poorest to 3.4% in the wealthiest quintile across all countries. The cascades were similar for boys and girls. In terms of dropout, 4% of children receiving BCG did not receive DPT1, 14% receiving DPT1 did not receive DPT3, and 9% receiving DPT3 did not progress to receive MCV.

INTERPRETATION

Focusing on zero-dose children is particularly important because those who are reached with the first vaccine are highly likely to also receive remaining vaccines.

Characterization of immunization secondary analyses using demographic and health surveys (DHS) and multiple indicator cluster surveys (MICS), 2006-2018

BACKGROUND

Infant immunization coverage worldwide has plateaued at about 85%. Using existing survey data to conduct analyses beyond estimating coverage may help immunization programmes better tailor strategies to reach un- and under-immunized children. The Demographic and Health Survey (DHS) and the Multiple Indicators Cluster Survey (MICS), routinely conducted in low and middle-income countries (LMICs), collect immunization data, yet vaccination coverage is often the only indicator reported and used. We conducted a review of published immunization-related analyses to characterize and quantify immunization secondary analyses done using DHS and MICS databases.

METHODS

We conducted a systematic search of the literature, of immunization-related secondary analyses from DHS or MICS published between 2006 and August 2018. We searched 15 electronic databases without language restrictions. For the articles included, relevant information was extracted and analyzed to summarize the characteristics of immunization-related secondary analyses. Results are presented following the PRISMA guidelines.

RESULTS

Among 1411 papers identified, 115 met our eligibility criteria; additionally, one article was supplemented by the Pan American Health Organization. The majority were published since 2012 (77.6%), and most (68.9%) had a first or corresponding author affiliated with institutions in high-income countries (as opposed to LMICs where these surveys are conducted). The median delay between survey implementation and publication of the secondary analysis was 5.4 years, with papers with authors affiliated to institutions in LMIC having a longer median publication delay (p < 0.001). Over 80% of the published analyses looked at factors associated with a specific vaccine or with full immunization. Quality proxies, such as reporting percent of immunization data from cards vs recall; occurrence and handling of missing data; whether survey analyses were weighted; and listing of potential biases or limitations of the original survey or analyses, were infrequently mentioned.

CONCLUSION

Our review suggests that more needs to be done to increase the increase the utilization of existing DHS and MICS datasets and improve the quality of the analyses to inform immunization programmes. This would include increasing the proportion of analyses done in LMICs, reducing the time lag between survey implementation and publication of additional analyses, and including more qualitative information about the survey in the publications to better interpret the results.