Vaccines

Editorial

4 pages, 163 KiB

Open AccessEditorial

“Humanly Possible”: Geographies, Metrics and Methods to Address Immunization Inequalities

by Devaki Nambiar, Ahmad Reza Hosseinpoor, Nicole Bergen, M. Carolina Danovaro-Holliday, Ciara E. Sugerman and Hope L. Johnson

Vaccines 2024, 12(9), 1062; https://doi.org/10.3390/vaccines12091062 (registering DOI) - 18 Sep 2024

Abstract

The year 2024 marks the 50th anniversary of the World Health Organization (WHO) Expanded Program on Immunization (EPI) [...] Full article

(This article belongs to the Special Issue Inequality in Immunization 2024)

Research

Jump to: Editorial, Review, Other

18 pages, 675 KiB

Open AccessArticle

Inequitable Distribution of Global Economic Benefits from Pneumococcal Conjugate Vaccination

by Fulgence Niyibitegeka, Fiona M. Russell, Mark Jit and Natalie Carvalho

Vaccines 2024, 12(7), 767; https://doi.org/10.3390/vaccines12070767 - 12 Jul 2024

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Abstract

Many low- and middle-income countries have been slow to introduce the pneumococcal conjugate vaccine (PCV) into their routine childhood immunization schedules despite a high burden of disease. We estimated the global economic surplus of PCV, defined as the sum of the net value [...] Read more.

Many low- and middle-income countries have been slow to introduce the pneumococcal conjugate vaccine (PCV) into their routine childhood immunization schedules despite a high burden of disease. We estimated the global economic surplus of PCV, defined as the sum of the net value to 194 countries (i.e., monetized health benefits minus net costs) and to vaccine manufacturers (i.e., profits). We further explored the distribution of global economic surplus across country income groups and manufacturers and the effect of different pricing strategies based on cross-subsidization, pooled procurement, and various tiered pricing mechanisms. We found that current PCV pricing policies disproportionately benefit high-income countries and manufacturers. Based on the 2021 birth cohort, high-income countries and manufacturers combined received 76.5% of the net economic benefits generated by the vaccine. Over the two decades of PCV availability, low- and middle-income countries have not received the full economic benefits of PCV. Cross-subsidization of the vaccine price for low- and middle-income countries and pooled procurement policies that would relate the vaccine price to the value of economic benefits generated for each country could reduce these inequalities. This analysis offers important considerations that may improve the equitable introduction and use of new and under-utilized vaccines. Full article

(This article belongs to the Special Issue Inequality in Immunization 2024)

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17 pages, 775 KiB

Open AccessArticle

Factors Associated with Uptake of Routine Measles-Containing Vaccine Doses among Young Children, Oromia Regional State, Ethiopia, 2021

by Abyot Bekele Woyessa, Monica P. Shah, Binyam Moges Azmeraye, Jeff Pan, Leuel Lisanwork, Getnet Yimer, Shu-Hua Wang, J. Pekka Nuorti, Miia Artama, Almea M. Matanock, Qian An, Paulos Samuel, Bekana Tolera, Birhanu Kenate, Abebe Bekele, Tesfaye Deti, Getachew Wako, Amsalu Shiferaw, Yohannes Lakew Tefera, Melkamu Ayalew Kokebie, Tatek Bogale Anbessie, Habtamu Teklie Wubie, Aaron Wallace and Ciara E. Sugerman Show full author list Hide full author list

Vaccines 2024, 12(7), 762; https://doi.org/10.3390/vaccines12070762 - 11 Jul 2024

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Abstract

Recommended vaccination at nine months of age with the measles-containing vaccine (MCV1) has been part of Ethiopia’s routine immunization program since 1980. A second dose of MCV (MCV2) was introduced in 2019 for children 15 months of age. We examined MCV1 and MCV2 [...] Read more.

Recommended vaccination at nine months of age with the measles-containing vaccine (MCV1) has been part of Ethiopia’s routine immunization program since 1980. A second dose of MCV (MCV2) was introduced in 2019 for children 15 months of age. We examined MCV1 and MCV2 coverage and the factors associated with measles vaccination status. A cross-sectional household survey was conducted among caregivers of children aged 12–35 months in selected districts of Oromia Region. Measles vaccination status was determined using home-based records, when available, or caregivers’ recall. We analyzed the association between MCV1 and MCV2 vaccination status and household, caregiver, and child factors using logistic regression. The caregivers of 1172 children aged 12–35 months were interviewed and included in the analysis. MCV1 and MCV2 coverage was 71% and 48%, respectively. The dropout rate (DOR) from the first dose of Pentavalent vaccine to MCV1 was 22% and from MCV1 to MCV2 was 46%. Caregivers were more likely to vaccinate their children with MCV if they gave birth at a health facility, believe that their child had received all recommended vaccines, and know the required number of vaccination visits and doses. MCV2 coverage was low, with a high measles dropout rate (DOR). Caregivers with high awareness of MCV and its schedule were more likely to vaccinate their children. Intensified demand generation, defaulter tracking, and vaccine-stock management should be strengthened to improve MCV uptake. Full article

(This article belongs to the Special Issue Inequality in Immunization 2024)

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19 pages, 725 KiB

Open AccessArticle

Timeliness of Childhood Vaccinations Following Strengthening of the Second Year of Life (2YL) Immunization Platform and Introduction of Catch-Up Vaccination Policy in Ghana

by Pierre Muhoza, Monica P. Shah, Kwame Amponsa-Achiano, Hongjiang Gao, Pamela Quaye, William Opare, Charlotte Okae, Philip-Neri Aboyinga, Joseph Kwadwo Larbi Opare, Daniel C. Ehlman, Melissa T. Wardle and Aaron S. Wallace

Vaccines 2024, 12(7), 716; https://doi.org/10.3390/vaccines12070716 - 27 Jun 2024

Viewed by 1662

Abstract

Strengthening routine immunization systems to successfully deliver childhood vaccines during the second year of life (2YL) is critical for vaccine-preventable disease control. In Ghana, the 18-month visit provides opportunities to deliver the second dose of the measles–rubella vaccine (MR2) and for healthcare workers [...] Read more.

Strengthening routine immunization systems to successfully deliver childhood vaccines during the second year of life (2YL) is critical for vaccine-preventable disease control. In Ghana, the 18-month visit provides opportunities to deliver the second dose of the measles–rubella vaccine (MR2) and for healthcare workers to assess for and provide children with any missed vaccine doses. In 2016, the Ghana Health Service (GHS) revised its national immunization policies to include guidelines for catch-up vaccinations. This study assessed the change in the timely receipt of vaccinations per Ghana’s Expanded Program on Immunizations (EPI) schedule, an important indicator of service quality, following the introduction of the catch-up policy and implementation of a multifaceted intervention package. Vaccination coverage was assessed from household surveys conducted in the Greater Accra, Northern, and Volta regions for 392 and 931 children aged 24–35 months with documented immunization history in 2016 and 2020, respectively. Age at receipt of childhood vaccines was compared to the recommended age, as per the EPI schedule. Cumulative days under-vaccinated during the first 24 months of life for each recommended dose were assessed. Multivariable Cox regression was used to assess the associations between child and caregiver characteristics and time to MR2 vaccination. From 2016 to 2020, the proportion of children receiving all recommended doses on schedule generally improved, the duration of under-vaccination was shortened for most doses, and higher coverage rates were achieved at earlier ages for the MR series. More timely infant doses and caregiver awareness of the 2YL visit were positively associated with MR2 vaccination. Fostering a well-supported cadre of vaccinators, building community demand for 2YL vaccination, sustaining service utilization through strengthened defaulter tracking and caregiver-reminder systems, and creating a favorable policy environment that promotes vaccination over the life course are critical to improving the timeliness of childhood vaccinations. Full article

(This article belongs to the Special Issue Inequality in Immunization 2024)

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14 pages, 1220 KiB

Open AccessArticle

Zero-Dose Childhood Vaccination Status in Rural Democratic Republic of Congo: Quantifying the Relative Impact of Geographic Accessibility and Attitudes toward Vaccination

by Branly Kilola Mbunga, Patrick Y. Liu, Freddy Bangelesa, Eric Mafuta, Nkamba Mukadi Dalau, Landry Egbende, Nicole A. Hoff, Jean Bosco Kasonga, Aimée Lulebo, Deogratias Manirakiza, Adèle Mudipanu, Nono Mvuama, Paul Ouma, Kerry Wong, Paul Lusamba and Roy Burstein

Vaccines 2024, 12(6), 617; https://doi.org/10.3390/vaccines12060617 - 4 Jun 2024

Viewed by 1224

Abstract

Despite efforts to increase childhood vaccination coverage in the Democratic Republic of the Congo (DRC), approximately 20% of infants have not started their routine immunization schedule (zero-dose). The present study aims to evaluate the relative influence of geospatial access to health facilities and [...] Read more.

Despite efforts to increase childhood vaccination coverage in the Democratic Republic of the Congo (DRC), approximately 20% of infants have not started their routine immunization schedule (zero-dose). The present study aims to evaluate the relative influence of geospatial access to health facilities and caregiver perceptions of vaccines on the vaccination status of children in rural DRC. Pooled data from two consecutive nationwide immunization surveys conducted in 2022 and 2023 were used. Geographic accessibility was assessed based on travel time from households to their nearest health facility using the AccessMod 5 model. Caregiver attitudes to vaccination were assessed using the survey question “How good do you think vaccines are for your child?” We used logistic regression to assess the relationship between geographic accessibility, caregiver attitudes toward vaccination, and their child’s vaccination status. Geographic accessibility to health facilities was high in rural DRC, with 88% of the population living within an hour’s walk to a health facility. Responding that vaccines are “Bad, Very Bad, or Don’t Know” relative to “Very Good” for children was associated with a many-fold increased odds of a zero-dose status (ORs 69.3 [95%CI: 63.4–75.8]) compared to the odds for those living 60+ min from a health facility, relative to <5 min (1.3 [95%CI: 1.1–1.4]). Similar proportions of the population fell into these two at-risk categories. We did not find evidence of an interaction between caregiver attitude toward vaccination and travel time to care. While geographic access to health facilities is crucial, caregiver demand appears to be a more important driver in improving vaccination rates in rural DRC. Full article

(This article belongs to the Special Issue Inequality in Immunization 2024)

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20 pages, 864 KiB

Open AccessArticle

Sociodemographic Trends and Correlation between Parental Hesitancy towards Pediatric COVID-19 Vaccines and Routine Childhood Immunizations in the United States: 2021–2022 National Immunization Survey—Child COVID Module

by Olufunto A. Olusanya, Nina B. Masters, Fan Zhang, David E. Sugerman, Rosalind J. Carter, Debora Weiss and James A. Singleton

Vaccines 2024, 12(5), 495; https://doi.org/10.3390/vaccines12050495 - 3 May 2024

Cited by 1 | Viewed by 1656

Abstract

Multiple factors may influence parental vaccine hesitancy towards pediatric COVID-19 vaccines and routine childhood immunizations (RCIs). Using the United States National Immunization Survey—Child COVID Module data collected from parents/guardians of children aged 5–11 years, this cross-sectional study (1) identified the trends and prevalence [...] Read more.

Multiple factors may influence parental vaccine hesitancy towards pediatric COVID-19 vaccines and routine childhood immunizations (RCIs). Using the United States National Immunization Survey—Child COVID Module data collected from parents/guardians of children aged 5–11 years, this cross-sectional study (1) identified the trends and prevalence estimates of parental hesitancy towards pediatric COVID-19 vaccines and RCIs, (2) examined the relationship between hesitancy towards pediatric COVID-19 vaccines and RCIs, and (3) assessed trends in parental hesitancy towards RCIs by sociodemographic characteristics and behavioral and social drivers of COVID-19 vaccination. From November 2021 to July 2022, 54,329 parents or guardians were interviewed. During this 9-month period, the proportion of parents hesitant about pediatric COVID-19 vaccines increased by 15.8 percentage points (24.8% to 40.6%). Additionally, the proportion of parents who reported RCIs hesitancy increased by 4.7 percentage points from November 2021 to May 2022 but returned to baseline by July 2022. Over nine months, parents’ concerns about pediatric COVID-19 infections declined; however, parents were increasingly worried about pediatric COVID-19 vaccine safety and overall importance. Furthermore, pediatric COVID-19 vaccine hesitancy was more prevalent among parents of children who were White (43.2%) versus Black (29.3%) or Hispanic (26.9%) and those residing in rural (51.3%) compared to urban (28.9%) areas. In contrast, RCIs hesitancy was higher among parents of children who were Black (32.0%) versus Hispanic (24.5%) or White (23.6%). Pediatric COVID-19 vaccine hesitancy was 2–6 times as prevalent among parents who were RCIs hesitant compared to those who were RCIs non-hesitant. This positive correlation between parental hesitancy towards pediatric COVID-19 vaccines and RCIs was observed for all demographic and psychosocial factors for unadjusted and adjusted prevalence ratios. Parent–provider interactions should increase vaccine confidence, shape social norms, and facilitate behavior change to promote pediatric vaccination rates. Full article

(This article belongs to the Special Issue Inequality in Immunization 2024)

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19 pages, 246 KiB

Open AccessArticle

Enhancing COVID-19 Vaccine Uptake among Tribal Communities: A Case Study on Program Implementation Experiences from Jharkhand and Chhattisgarh States, India

by Ankita Meghani, Manjula Sharma, Tanya Singh, Sourav Ghosh Dastidar, Veena Dhawan, Natasha Kanagat, Anil Gupta, Anumegha Bhatnagar, Kapil Singh, Jessica C. Shearer and Gopal Krishna Soni

Vaccines 2024, 12(5), 463; https://doi.org/10.3390/vaccines12050463 - 26 Apr 2024

Viewed by 1367

Abstract

Tribal populations in India have health care challenges marked by limited access due to geographical distance, historical isolation, cultural differences, and low social stratification, and that result in weaker health indicators compared to the general population. During the pandemic, Tribal districts consistently reported [...] Read more.

Tribal populations in India have health care challenges marked by limited access due to geographical distance, historical isolation, cultural differences, and low social stratification, and that result in weaker health indicators compared to the general population. During the pandemic, Tribal districts consistently reported lower COVID-19 vaccination coverage than non-Tribal districts. We assessed the MOMENTUM Routine Immunization Transformation and Equity (the project) strategy, which aimed to increase access to and uptake of COVID-19 vaccines among Tribal populations in Chhattisgarh and Jharkhand using the reach, effectiveness, adoption, implementation, and maintenance framework. We designed a qualitative explanatory case study and conducted 90 focus group discussions and in-depth interviews with Tribal populations, community-based nongovernmental organizations that worked with district health authorities to implement the interventions, and other stakeholders such as government and community groups. The active involvement of community leaders, targeted counseling, community gatherings, and door-to-door visits appeared to increase vaccine awareness and assuage concerns about its safety and efficacy. Key adaptations such as conducting evening vaccine awareness activities, holding vaccine sessions at flexible times and sites, and modifying messaging for booster doses appeared to encourage vaccine uptake among Tribal populations. While we used project resources to mitigate financial and supply constraints where they arose, sustaining long-term uptake of project interventions appears dependent on continued funding and ongoing political support. Full article

(This article belongs to the Special Issue Inequality in Immunization 2024)

10 pages, 1420 KiB

Open AccessArticle

The Impact of the Coronavirus Pandemic on Vaccination Coverage in Latin America and the Caribbean

by Ignacio E. Castro-Aguirre, Dan Alvarez, Marcela Contreras, Silas P. Trumbo, Oscar J. Mujica, Daniel Salas Peraza and Martha Velandia-González

Vaccines 2024, 12(5), 458; https://doi.org/10.3390/vaccines12050458 - 25 Apr 2024

Cited by 1 | Viewed by 1222

Abstract

Background: Routine vaccination coverage in Latin America and the Caribbean declined prior to and during the coronavirus pandemic. We assessed the pandemic’s impact on national coverage levels and analyzed whether financial and inequality indicators, immunization policies, and pandemic policies were associated with changes [...] Read more.

Background: Routine vaccination coverage in Latin America and the Caribbean declined prior to and during the coronavirus pandemic. We assessed the pandemic’s impact on national coverage levels and analyzed whether financial and inequality indicators, immunization policies, and pandemic policies were associated with changes in national and regional coverage levels. Methodology: We compared first- and third-dose coverage of diphtheria–pertussis–tetanus-containing vaccine (DTPcv) with predicted coverages using time series forecast modeling for 39 LAC countries and territories. Data were from the PAHO/WHO/UNICEF Joint Reporting Form. A secondary analysis of factors hypothesized to affect coverages during the pandemic was also performed. Results: In total, 31 of 39 countries and territories (79%) had greater-than-predicted declines in DTPcv1 and DTPcv3 coverage during the pandemic, with 9 and 12 of these, respectively, falling outside the 95% confidence interval. Within-country income inequality (i.e., Gini coefficient) was associated with significant declines in DTPcv1 coverage, and cross-country income inequality was associated with declines in DTPcv1 and DTPcv3 coverages. Observed absolute and relative inequality gaps in DTPcv1 and DTPcv3 coverage between extreme country quintiles of income inequality (i.e., Q1 vs. Q5) were accentuated in 2021, as compared with the 2019 observed and 2021 predicted values. We also observed a trend between school closures and greater-than-predicted declines in DTPcv3 coverage that approached statistical significance (p = 0.06). Conclusion: The pandemic exposed vaccination inequities in LAC and significantly impacted coverage levels in many countries. New strategies are needed to reattain high coverage levels. Full article

(This article belongs to the Special Issue Inequality in Immunization 2024)

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25 pages, 3170 KiB

Open AccessArticle

Comparison of Wealth-Related Inequality in Tetanus Vaccination Coverage before and during Pregnancy: A Cross-Sectional Analysis of 72 Low- and Middle-Income Countries

by Nicole E. Johns, Cauane Blumenberg, Katherine Kirkby, Adrien Allorant, Francine Dos Santos Costa, M. Carolina Danovaro-Holliday, Carrie Lyons, Nasir Yusuf, Aluísio J. D. Barros and Ahmad Reza Hosseinpoor

Vaccines 2024, 12(4), 431; https://doi.org/10.3390/vaccines12040431 - 17 Apr 2024

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Abstract

Immunization of pregnant women against tetanus is a key strategy for reducing tetanus morbidity and mortality while also achieving the goal of maternal and neonatal tetanus elimination. Despite substantial progress in improving newborn protection from tetanus at birth through maternal immunization, umbilical cord [...] Read more.

Immunization of pregnant women against tetanus is a key strategy for reducing tetanus morbidity and mortality while also achieving the goal of maternal and neonatal tetanus elimination. Despite substantial progress in improving newborn protection from tetanus at birth through maternal immunization, umbilical cord practices and sterilized and safe deliveries, inequitable gaps in protection remain. Notably, an infant’s tetanus protection at birth is comprised of immunization received by the mother during and before the pregnancy (e.g., through childhood vaccination, booster doses, mass vaccination campaigns, or during prior pregnancies). In this work, we examine wealth-related inequalities in maternal tetanus toxoid containing vaccination coverage before pregnancy, during pregnancy, and at birth for 72 low- and middle-income countries with a recent Demographic and Health Survey or Multiple Indicator Cluster Survey (between 2013 and 2022). We summarize coverage levels and absolute and relative inequalities at each time point; compare the relative contributions of inequalities before and during pregnancy to inequalities at birth; and examine associations between inequalities and coverage levels. We present the findings for countries individually and on aggregate, by World Bank country income grouping, as well as by maternal and neonatal tetanus elimination status, finding that most of the inequality in tetanus immunization coverage at birth is introduced during pregnancy. Inequalities in coverage during pregnancy are most pronounced in low- and lower-middle-income countries, and even more so in countries which have not achieved maternal and neonatal tetanus elimination. These findings suggest that pregnancy is a key time of opportunity for equity-oriented interventions to improve maternal tetanus immunization coverage. Full article

(This article belongs to the Special Issue Inequality in Immunization 2024)

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10 pages, 1975 KiB

Open AccessArticle

Analyzing Subnational Immunization Coverage to Catch up and Reach the Unreached in Seven High-Priority Countries in the Eastern Mediterranean Region, 2019–2021

by Kamal Fahmy, Quamrul Hasan, Md Sharifuzzaman and Yvan Hutin

Vaccines 2024, 12(3), 285; https://doi.org/10.3390/vaccines12030285 - 8 Mar 2024

Viewed by 1362

Abstract

Yearly national immunization coverage reporting does not measure performance at the subnational level throughout the year and conceals inequalities within countries. We analyzed subnational immunization coverage from seven high-priority countries in our region. We analyzed subnational, monthly immunization data from seven high-priority countries. [...] Read more.

Yearly national immunization coverage reporting does not measure performance at the subnational level throughout the year and conceals inequalities within countries. We analyzed subnational immunization coverage from seven high-priority countries in our region. We analyzed subnational, monthly immunization data from seven high-priority countries. Five were Gavi eligible (i.e., Afghanistan, Pakistan, Somalia, Syria, and Yemen); these are countries that according to their low income are eligible for support from the Global Alliance on Vaccine and Immunization, while Iraq and Jordan were included because of a recent decrease in immunization coverage and contribution to the regional number of under and unimmunized children. DTP3 coverage, which is considered as the main indicator for the routine immunization coverage as the essential component of the immunization program performance, varied monthly in 2019–2021 before reaching pre-pandemic coverage in the last two months of 2021. Somalia and Yemen had a net gain in DTP3 coverage at the end of 2021, as improvement in 2021 exceeded the regression in 2020. In Pakistan and Iraq, DTP3 improvement in 2021 equaled the 2020 regression. In Afghanistan, Syria and Jordan, the regression in DTP3 coverage continued in 2020 and 2021. The number of districts with at least 6000 zero-dose children improved moderately in Afghanistan and substantially in Somalia throughout the follow-up period. In Pakistan, the geographical distribution differed between 2020 and 2021.Of the three countries with the highest number of zero-dose children, DTP1 coverage reached 109% in Q4 of 2020 after a sharp drop to 69% in Q2 of 2020. However, in Pakistan, the number of zero-dose children decreased to 1/10 of its burden in Q4 of 2021. In Afghanistan, the number of zero-dose children more than a doubled. Among the even countries, adaptation of immunization service to the pandemic varied, depending on the agility of the health system and the performance of the components of the expanded program on immunization. We recommended monitoring administrative monthly immunization coverage data at the subnational level to detect low-performing districts, plan catchup, identify bottlenecks towards reaching unvaccinated children and customize strategies to improve the coverage in districts with zero-dose children throughout the year and monitor progress. Full article

(This article belongs to the Special Issue Inequality in Immunization 2024)

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20 pages, 11085 KiB

Open AccessArticle

Geospatial Analyses of Recent Household Surveys to Assess Changes in the Distribution of Zero-Dose Children and Their Associated Factors before and during the COVID-19 Pandemic in Nigeria

by Justice Moses K. Aheto, Iyanuloluwa Deborah Olowe, Ho Man Theophilus Chan, Adachi Ekeh, Boubacar Dieng, Biyi Fafunmi, Hamidreza Setayesh, Brian Atuhaire, Jessica Crawford, Andrew J. Tatem and Chigozie Edson Utazi

Vaccines 2023, 11(12), 1830; https://doi.org/10.3390/vaccines11121830 - 8 Dec 2023

Cited by 1 | Viewed by 2699

Abstract

The persistence of geographic inequities in vaccination coverage often evidences the presence of zero-dose and missed communities and their vulnerabilities to vaccine-preventable diseases. These inequities were exacerbated in many places during the coronavirus disease 2019 (COVID-19) pandemic, due to severe disruptions to vaccination [...] Read more.

The persistence of geographic inequities in vaccination coverage often evidences the presence of zero-dose and missed communities and their vulnerabilities to vaccine-preventable diseases. These inequities were exacerbated in many places during the coronavirus disease 2019 (COVID-19) pandemic, due to severe disruptions to vaccination services. Understanding changes in zero-dose prevalence and its associated risk factors in the context of the COVID-19 pandemic is, therefore, critical to designing effective strategies to reach vulnerable populations. Using data from nationally representative household surveys conducted before the COVID-19 pandemic, in 2018, and during the pandemic, in 2021, in Nigeria, we fitted Bayesian geostatistical models to map the distribution of three vaccination coverage indicators: receipt of the first dose of diphtheria-tetanus-pertussis-containing vaccine (DTP1), the first dose of measles-containing vaccine (MCV1), and any of the four basic vaccines (bacilli Calmette-Guerin (BCG), oral polio vaccine (OPV0), DTP1, and MCV1), and the corresponding zero-dose estimates independently at a 1 × 1 km resolution and the district level during both time periods. We also explored changes in the factors associated with non-vaccination at the national and regional levels using multilevel logistic regression models. Our results revealed no increases in zero-dose prevalence due to the pandemic at the national level, although considerable increases were observed in a few districts. We found substantial subnational heterogeneities in vaccination coverage and zero-dose prevalence both before and during the pandemic, showing broadly similar patterns in both time periods. Areas with relatively higher zero-dose prevalence occurred mostly in the north and a few places in the south in both time periods. We also found consistent areas of low coverage and high zero-dose prevalence using all three zero-dose indicators, revealing the areas in greatest need. At the national level, risk factors related to socioeconomic/demographic status (e.g., maternal education), maternal access to and utilization of health services, and remoteness were strongly associated with the odds of being zero dose in both time periods, while those related to communication were mostly relevant before the pandemic. These associations were also supported at the regional level, but we additionally identified risk factors specific to zero-dose children in each region; for example, communication and cross-border migration in the northwest. Our findings can help guide tailored strategies to reduce zero-dose prevalence and boost coverage levels in Nigeria. Full article

(This article belongs to the Special Issue Inequality in Immunization 2024)

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Review

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18 pages, 1351 KiB

Open AccessReview

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

by Carrie Lyons, Devaki Nambiar, Nicole E. Johns, Adrien Allorant, Nicole Bergen and Ahmad Reza Hosseinpoor

Vaccines 2024, 12(8), 850; https://doi.org/10.3390/vaccines12080850 - 29 Jul 2024

Viewed by 838

Abstract

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 [...] Read more.

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. Full article

(This article belongs to the Special Issue Inequality in Immunization 2024)

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15 pages, 896 KiB

Open AccessReview

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

by Anna Kalbarczyk, Natasha Brownlee and Elizabeth Katz

Vaccines 2024, 12(6), 625; https://doi.org/10.3390/vaccines12060625 - 5 Jun 2024

Viewed by 1338

Abstract

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 [...] Read more.

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. Full article

(This article belongs to the Special Issue Inequality in Immunization 2024)

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Other

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17 pages, 2168 KiB

Open AccessProject Report

Building Data Triangulation Capacity for Routine Immunization and Vaccine Preventable Disease Surveillance Programs to Identify Immunization Coverage Inequities

by Audrey Rachlin, Oluwasegun Joel Adegoke, Rajendra Bohara, Edson Rwagasore, Hassan Sibomana, Adeline Kabeja, Ines Itanga, Samuel Rwunganira, Blaise Mafende Mario, Nahimana Marie Rosette, Ramatu Usman Obansa, Angela Ukpojo Abah, Olorunsogo Bidemi Adeoye, Ester Sikare, Eugene Lam, Christopher S. Murrill and Angela Montesanti Porter

Vaccines 2024, 12(6), 646; https://doi.org/10.3390/vaccines12060646 - 11 Jun 2024

Viewed by 1456

Abstract

The Expanded Programme on Immunization (EPI) and Vaccine Preventable Disease (VPD) Surveillance (VPDS) programs generate multiple data sources (e.g., routine administrative data, VPD case data, and coverage surveys). However, there are challenges with the use of these siloed data for programmatic decision-making, including [...] Read more.

The Expanded Programme on Immunization (EPI) and Vaccine Preventable Disease (VPD) Surveillance (VPDS) programs generate multiple data sources (e.g., routine administrative data, VPD case data, and coverage surveys). However, there are challenges with the use of these siloed data for programmatic decision-making, including poor data accessibility and lack of timely analysis, contributing to missed vaccinations, immunity gaps, and, consequently, VPD outbreaks in populations with limited access to immunization and basic healthcare services. Data triangulation, or the integration of multiple data sources, can be used to improve the availability of key indicators for identifying immunization coverage gaps, under-immunized (UI) and un-immunized (zero-dose (ZD)) children, and for assessing program performance at all levels of the healthcare system. Here, we describe the data triangulation processes, prioritization of indicators, and capacity building efforts in Bangladesh, Nigeria, and Rwanda. We also describe the analyses used to generate meaningful data, key indicators used to identify immunization coverage inequities and performance gaps, and key lessons learned. Triangulation processes and lessons learned may be leveraged by other countries, potentially leading to programmatic changes that promote improved access and utilization of vaccination services through the identification of UI and ZD children. Full article

(This article belongs to the Special Issue Inequality in Immunization 2024)

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11 pages, 242 KiB

Open AccessPerspective

Measuring Zero-Dose Children: Reflections on Age Cohort Flexibilities for Targeted Immunization Surveys at the Local Level

by Gustavo C. Corrêa, Md. Jasim Uddin, Tasnuva Wahed, Elizabeth Oliveras, Christopher Morgan, Moses R. Kamya, Patience Kabatangare, Faith Namugaya, Dorothy Leab, Didier Adjakidje, Patrick Nguku, Adam Attahiru, Jenny Sequeira, Nancy Vollmer and Heidi W. Reynolds

Vaccines 2024, 12(2), 195; https://doi.org/10.3390/vaccines12020195 - 14 Feb 2024

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Abstract

Zero-dose (ZD) children is a critical objective in global health, and it is at the heart of the Immunization Agenda 2030 (IA2030) strategy. Coverage for the first dose of diphtheria–tetanus–pertussis (DTP1)-containing vaccine is the global operational indicator used to estimate ZD children. When [...] Read more.

Zero-dose (ZD) children is a critical objective in global health, and it is at the heart of the Immunization Agenda 2030 (IA2030) strategy. Coverage for the first dose of diphtheria–tetanus–pertussis (DTP1)-containing vaccine is the global operational indicator used to estimate ZD children. When surveys are used, DTP1 coverage estimates usually rely on information reported from caregivers of children aged 12–23 months. It is important to have a global definition of ZD children, but learning and operational needs at a country level may require different ZD measurement approaches. This article summarizes a recent workshop discussion on ZD measurement for targeted surveys at local levels related to flexibilities in age cohorts of inclusion from the ZD learning Hub (ZDLH) initiative—a learning initiative involving 5 consortia of 14 different organizations across 4 countries—Bangladesh, Mali, Nigeria, and Uganda—and a global learning partner. Those considerations may include the need to generate insights on immunization timeliness and on catch-up activities, made particularly relevant in the post-pandemic context; the need to compare results across different age cohort years to better identify systematically missed communities and validate programmatic priorities, and also generate insights on changes under dynamic contexts such as the introduction of a new ZD intervention or for recovering from the impact of health system shocks. Some practical considerations such as the potential need for a larger sample size when including comparisons across multiple cohort years but a potential reduction in the need for household visits to find eligible children, an increase in recall bias when older age groups are included and a reduction in recall bias for the first year of life, and a potential reduction in sample size needs and time needed to detect impact when the first year of life is included. Finally, the inclusion of the first year of life cohort in the survey may be particularly relevant and improve the utility of evidence for decision-making and enable its use in rapid learning cycles, as insights will be generated for the population being currently targeted by the program. For some of those reasons, the ZDLH initiative decided to align on a recommendation to include the age cohort from 18 weeks to 23 months, with enough power to enable disaggregation of key results across the two different cohort years. We argue that flexibilities with the age cohort for inclusion in targeted surveys at the local level may be an important principle to be considered. More research is needed to better understand in which contexts improvements in timeliness of DTP1 in the first year of life will translate to improvements in ZD results in the age cohort of 12–23 months as defined by the global DTP1 indicator. Full article

(This article belongs to the Special Issue Inequality in Immunization 2024)

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