Decomposing the gap in missed opportunities for vaccination between poor and non-poor in sub-Saharan Africa: A Multicountry Analyses

How did the introduction of the measles-containing vaccine second dose (MCV2) affect measles vaccine uptake? - evidence from Nigeria

Nigeria has the highest burden of measles worldwide, as measles vaccine uptake remains low. Recently, the second dose of the measles-containing vaccine (MCV2) was introduced as part of the routine immunization (RI) program, and this study examined how it changed the uptake of the measles vaccine and the factors associated with vaccination behavior. The Nigeria Multiple Indicator Cluster Survey (MICS) 2021 was used to compare measles vaccination uptake as well as factors associated with vaccination uptake between children before MCV2 introduction (cohort 1) and after the introduction (cohort 2). The overall rate of measles vaccine uptake was higher among cohort 1 (64%-95%) than among cohort 2 (56%-92%) in all zones because of younger age among cohort 2. The dropout from the first to second measles vaccines was similar between the cohorts (around 24%). Higher maternal education levels and higher household wealth levels were both correlated with the vaccine uptake or both cohorts but a positive correlation between the dropout and mother's education level was observed only among cohort 2, especially in the North West and South West zones. The positive correlation between the dropout and mother's education level among cohort 2 indicates that the introduction of MCV2 as part of RI might have helped to narrow the disparity in measles vaccine uptake in North West and South West zones. Further study is required to investigate strategies employed to reduce the disparity in these zones to apply nationwide.

Exploring the "Urban Advantage" in Access to Immunization Services: A Comparison of Zero-Dose Prevalence Between Rural, and Poor and Non-poor Urban Households Across 97 Low- and Middle-Income Countries

Urban children are more likely to be vaccinated than rural children, but that advantage is not evenly distributed. Children living in poor urban areas face unique challenges, living far from health facilities and with lower-quality health services, which can impact their access to life-saving vaccines. Our goal was to compare the prevalence of zero-dose children in poor and non-poor urban and rural areas of low- and middle-income countries (LMICs). Zero-dose children were those who failed to receive any dose of a diphtheria-pertussis-tetanus (DPT) containing vaccine. We used data from nationally representative household surveys of 97 LMICs to investigate 201,283 children aged 12-23 months. The pooled prevalence of zero-dose children was 6.5% among the urban non-poor, 12.6% for the urban poor, and 14.7% for the rural areas. There were significant differences between these areas in 43 countries. In most of these countries, the non-poor urban children were at an advantage compared to the urban poor, who were still better off or similar to rural children. Our results emphasize the inequalities between urban and rural areas, but also within urban areas, highlighting the challenges faced by poor urban and rural children. Outreach programs and community interventions that can reach poor urban and rural communities-along with strengthening of current vaccination programs and services-are important steps to reduce inequalities and ensure that no child is left unvaccinated.

The influence of demographic and socio-economic factors on non-vaccination, under-vaccination and missed opportunities for vaccination amongst children 0-23 months in Kenya for the period 2003-2014

Vaccination is crucial in reducing child mortality and the prevalence of Vaccine-Preventable-Diseases (VPD), especially in low-and-middle-income countries like Kenya. However, non-vaccination, under-vaccination, and missed opportunities for vaccination (MOV) pose significant challenges to these efforts. This study aimed to analyze the impact of demographic and socio-economic factors on non-vaccination, under-vaccination, and MOV among children aged 0-23 months in Kenya from 2003 to 2014. A secondary data analysis of data from the Kenya Demographic Health Surveys (KDHS) conducted during this period was conducted, with a total of 11,997 participants, using a two-stage, multi-stage, and stratified sampling technique. The study examined factors such as child's sex, residence, mother's age, marital status, religion, birth order, maternal education, wealth quintile, province, child's birth order, parity, number of children in the household, place of delivery, and mother's occupation. Binary logistic regression was employed to identify the determinants of non-vaccination, under-vaccination, and MOV, and multivariable logistic regression analysis to report odds ratios (OR) and their corresponding 95% confidence intervals (CI). In 2003, the likelihood of non-vaccination decreased with higher maternal education levels: mothers who did not complete primary education (AOR = 0.55, 95% CI = 0.37-0.81), completed primary education (AOR = 0.34, 95% CI = 0.21-0.56), and had secondary education or higher (AOR = 0.26, 95% CI = 0.14-0.50) exhibited decreasing probabilities. In 2008/09, divorced/separated/widowed mothers (AOR = 0.22, 95% CI = 0.07-0.65) and those with no religion (AOR = 0.37, 95% CI = 0.17-0.81) showed lower odds of non-vaccination, while lower wealth quintiles were associated with higher odds. In 2014, non-vaccination was higher among younger mothers aged 15-19 years (AOR = 12.53, 95% CI = 1.59-98.73), in North Eastern Province (AOR = 7.15, 95% CI = 2.02-25.30), in families with more than 5 children (AOR = 4.19, 95% CI = 1.09-16.18), and in children born at home (AOR = 4.47, 95% CI = 1.32-15.17). Similar patterns were observed for under-vaccination and MOV. This information can inform strategies for bridging the gaps in immunization coverage and promoting equitable vaccination practices in Kenya.

Systematic review of social determinants of childhood immunisation in low- and middle-income countries and equity impact analysis of childhood vaccination coverage in Nigeria

BACKGROUND

Nigeria has a high proportion of the world's underimmunised children. We estimated the inequities in childhood immunisation coverage associated with socioeconomic, geographic, maternal, child, and healthcare characteristics among children aged 12-23 months in Nigeria using a social determinants of health perspective.

METHODS

We conducted a systematic review to identify the social determinants of childhood immunisation associated with inequities in vaccination coverage among low- and middle-income countries. Using the 2018 Nigeria Demographic and Health Survey (DHS), we conducted multiple logistic regression to estimate the association between basic childhood vaccination coverage (1-dose BCG, 3-dose DTP-HepB-Hib (diphtheria, tetanus, pertussis, hepatitis B and Haemophilus influenzae type B), 3-dose polio, and 1-dose measles) and socioeconomic, geographic, maternal, child, and healthcare characteristics in Nigeria.

RESULTS

From the systematic review, we identified the key determinants of immunisation to be household wealth, religion, and ethnicity for socioeconomic characteristics; region and place of residence for geographic characteristics; maternal age at birth, maternal education, and household head status for maternal characteristics; sex of child and birth order for child characteristics; and antenatal care and birth setting for healthcare characteristics. Based of the 2018 Nigeria DHS analysis of 6,059 children aged 12-23 months, we estimated that basic vaccination coverage was 31% (95% CI: 29-33) among children aged 12-23 months, whilst 19% (95% CI:18-21) of them were zero-dose children who had received none of the basic vaccines. After controlling for background characteristics, there was a significant increase in the odds of basic vaccination by household wealth (AOR: 3.21 (2.06, 5.00), p < 0.001) for the wealthiest quintile compared to the poorest quintile, antenatal care of four or more antenatal care visits compared to no antenatal care (AOR: 2.87 (2.21, 3.72), p < 0.001), delivery in a health facility compared to home births (AOR 1.32 (1.08, 1.61), p = 0.006), relatively older maternal age of 35-49 years compared to 15-19 years (AOR: 2.25 (1.46, 3.49), p < 0.001), and maternal education of secondary or higher education compared to no formal education (AOR: 1.79 (1.39, 2.31), p < 0.001). Children of Fulani ethnicity in comparison to children of Igbo ethnicity had lower odds of receiving basic vaccinations (AOR: 0.51 (0.26, 0.97), p = 0.039).

CONCLUSIONS

Basic vaccination coverage is below target levels for all groups. Children from the poorest households, of Fulani ethnicity, who were born in home settings, and with young mothers with no formal education nor antenatal care, were associated with lower odds of basic vaccination in Nigeria. We recommend a proportionate universalism approach for addressing the immunisation barriers in the National Programme on Immunization of Nigeria.

Missed opportunities for vaccination at point of care and their impact on coverage and urban-rural coverage inequity in the Gambia

INTRODUCTION

Identifying actionable targets is crucial to improve overall and equity in vaccination coverage, and in line with the global Immunization Agenda 2030. Therefore, this study seeks to assess the prevalence of missed opportunities for simultaneous vaccination (MOSVs) and their impact on vaccination coverage and urban-rural inequity in The Gambia.

METHODS

We used data of children aged 12-23 months from The Gambia 2019/2020 demographic and health survey (weighted n = 1355) with seen vaccination cards. We analyzed: the frequency of MOSVs; percentage point coverage reduction attributable to MOSVs for 18 vaccine doses and full basic vaccination; and MOSVs' contribution to urban-rural coverage inequity through Blinder-Oaxaca decomposition.

RESULTS

Sixty percent of children experienced MOSVs, in both urban and rural areas, but urban MOSVs were more seldom corrected (35.9 % vs 45.3 %). All eighteen vaccine doses assessed could have achieved between one to eleven percentage points higher coverage if MOSVs had been avoided, with full basic vaccination gaining even more. While MOSV correction did not impact overall urban-rural coverage inequity, it did exacerbate (explained coefficient = -0.1007; P = 0.002) inequities among children who experienced MOSVs, explaining 95 % of the observed difference.

CONCLUSION

Our study highlights the prevalence and negative impact of MOSVs on overall vaccination coverage. Although MOSVs did not contribute significantly to the total urban-rural inequity in coverage, they have detrimental effects on vaccination coverage and urban-rural inequity among children who had experienced MOSVs. Addressing MOSVs, can enhance coverage and reduce the risk of under-vaccination, aligning with global initiatives.

Inequalities in utilisation of essential antenatal services for women with disabilities in Pakistan: analysis of a cross-sectional demographic and health survey of Pakistan 2017-2018

OBJECTIVES

Although the number of disabled women entering motherhood is growing, there is little quantitative evidence about the utilisation of essential antenatal care (ANC) services by women with disabilities. We examined inequalities in the use of essential ANC services between women with and without disabilities.

DESIGN, SETTING AND ANALYSIS

A secondary analysis of cross-sectional data from recent Demographic and Health Survey of Pakistan 2017-2018 was performed using logistic regression.

PARTICIPANTS

A total weighted sample of 6791 ever-married women (age 15-49) who had a live birth in the 5 years before the survey were included.

OUTCOME MEASURES

Utilisation of ANC: (A) antenatal coverage: (1) received ANC and (2) completed four or more ANC visits and (B) utilisation of essential components of ANC.

RESULTS

The percentage of women who were at risk of disability and those living with disability in one or more domains was 11.5% and 2.6%, respectively. The coverage of ANC did not differ by disability status. With utilisation of essential ANC components, consumption of iron was lower (adjusted OR, aOR=0.6; p<0.05), while advice on exclusive breast feeding (aOR=1.6; p<0.05) and urine test (aOR=1.7; p<0.05) was higher among women with disabilities as compared with their counterparts. Similarly, the odds of receiving advice on maintaining a balanced diet was higher (aOR=1.3; p<0.05) among women at risk of any disability as opposed to their counterparts. Differences were also found for these same indicators in subgroup analysis by wealth status (poor/non-poor) and place of residence (urban-rural).

CONCLUSION

Our study did not find glaring inequalities in the utilisation of ANC services between women with disabilities and non-disabled women. This was true for urban versus rural residence and among the poor versus non-poor women. Some measures, however, should be made to improve medication compliance among women with disabilities.

Wealth inequalities in reproductive and child health preventive care in Mozambique: a decomposition analysis

Background

Assessing the gap between rich and poor is important to monitor inequalities in health. Identifying the contribution to that gap can help policymakers to develop interventions towards decreasing that difference.

Objective

To quantify the wealth inequalities in health preventive measures (bed net use, vaccination, and contraceptive use) to determine the demographic and socioeconomic contribution factors to that inequality using a decomposition analysis.

Methods

Data from the 2015 Immunisation, Malaria and AIDs Indicators Survey were used. The total sample included 6946 women aged 15–49 years. Outcomes were use of insecticide-treated nets (ITN), child vaccination, and modern contraception use. Wealth Index was the exposure variable and age, marital status, place of residence, region, education, occupation, and household wealth index were the explanatory variables. Wealth inequalities were assessed using concentration indexes (Cindex). Wagstaff-decomposition analysis was conducted to assess the determinants of the wealth inequality.

Results

The Cindex was −0.081 for non-ITN, −0.189 for lack of vaccination coverage and −0.284 for non-contraceptive use, indicating a pro-poor inequality. The results revealed that 88.41% of wealth gap for ITN was explained by socioeconomic factors, with education and wealth playing the largest roles. Lack of full vaccination, socioeconomic factors made the largest contribution, through the wealth variable, whereas geographic factors came next. Finally, the lack of contraceptive use, socioeconomic factors were the main explanatory factors, but to a lesser degree than the other two outcomes, with wealth and education contributing most to explaining the gap.

Conclusion

There was a pro-poor inequality in reproductive and child preventive measures in Mozambique. The greater part of this inequality could be attributed to wealth, education, and residence in rural areas. Resources should be channeled into poor and non-educated rural communities to tackle these persistent inequities in preventive care.

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).

Missed opportunities for vaccination (MOV) in children up to 5 years old in 19 Médecins Sans Frontières-supported health facilities: a cross-sectional survey in six low-resource countries

OBJECTIVE

To describe missed opportunities for vaccination (MOV) among children visiting Médecins Sans Frontières (MSF)-supported facilities, their related factors, and to identify reasons for non-vaccination.

DESIGN

Cross-sectional surveys conducted between 2011 and 2015.

SETTING AND PARTICIPANTS

Children up to 59 months of age visiting 19 MSF-supported facilities (15 primary healthcare centres and four hospitals) in Afghanistan, Democratic Republic of the Congo, Mauritania, Niger, Pakistan and South Sudan. Only children whose caregivers presented their vaccination card were included.

OUTCOME MEASURES

We describe MOV prevalence and reasons for no vaccination. We also assess the association of MOV with age, type of facility and reason for visit.

RESULTS

Among 5055 children's caregivers interviewed, 2738 presented a vaccination card of whom 62.8% were eligible for vaccination, and of those, 64.6% had an MOV. Presence of MOV was more likely in children visiting a hospital or a health facility for a reason other than vaccination. MOV occurrence was significantly higher among children aged 12-23 months (84.4%) and 24-59 months (88.3%) compared with children below 12 months (56.2%, p≤0.001). Main reasons reported by caregivers for MOV were lack of vaccines (40.3%), reason unknown (31.2%) and not being informed (17.6%).

CONCLUSIONS

Avoiding MOV should remain a priority in low-resource settings, in line with the new 'Immunization Agenda 2030'. Children beyond their second year of life are particularly vulnerable for MOV. We strongly recommend assessment of eligibility for vaccination as routine healthcare practice regardless of the reason for the visit by screening vaccination card. Strengthening implementation of 'Second year of life' visits and catch-up activities are proposed strategies to reduce MOV.

Missed opportunities for vaccination in Peru 2010-2020: A study of socioeconomic inequalities

Background

Missed Opportunities for Vaccination (MOV) represent a major risk in the re-emergence of immunopreventable diseases. However, in the region, there are few published studies on MOVs using national databases such as demographic and health surveys (DHS). This study aims to describe the frequency and trends of MOVs for the first dose of vaccines against the leading causes of infant morbidity and mortality, their complete vaccination coverage, and trends in socioeconomic inequalities at the national and departmental levels for an 11-years period.

Methods

Using DHS data from an 11-year period (2010-2020), we calculated frequencies and trends in MOVs of vaccines for the leading causes of child morbidity and mortality, estimated inequalities in MOVs using the Slope Inequality Index (SII) and conducted a spatial autocorrelation test to identify clusters of higher or lower inequality in MOVs at the national level.

Findings

We found that, at the national level, greater inequality was concentrated in the wealthiest categories of each socioeconomic variable. We identified that departments with higher poverty rates concentrated higher levels of inequality in the MOVs in the lowest strata of the socioeconomic variables. In addition, we found that some departments with similar geographic and socioeconomic characteristics had spatially correlated levels of inequality on MOVs.

Interpretation

These findings can help to identify the heterogeneity that exists in the distribution of MOVs among departments and socioeconomic strata, which would help to prioritize specific areas and subpopulations for national immunization strategies.

Funding

No additional funding source was required for this study.

Drivers of long-lasting insecticide-treated net utilisation and parasitaemia among under-five children in 13 States with high malaria burden in Nigeria

BACKGROUND

Although Nigeria has made some progress in malaria control, there are variations across States. We investigated the factors associated with utilisation of long-lasting insecticide-treated net (LLIN) and parasitaemia among under-five children in 13 States with high malaria burden.

METHOD

Data from the 2015 Nigeria Malaria Indicator Survey and 2018 Demographic and Health Survey were obtained and analysed. The 2015 and 2018 data were compared to identify States with increase or reduction in parasitaemia. Analysis was done for all the 13 study States; four States with increased parasitaemia and nine States with reduction. Random-effects logit models were fitted to identify independent predictors of LLIN utilisation and parasitaemia.

RESULTS

LLIN was used by 53.4% of 2844 children, while parasitaemia prevalence was 26.4% in 2018. Grandchildren (AOR = 5.35, CI: 1.09-26.19) were more likely to use LLIN while other relatives (AOR = 0.33, CI: 0.11-0.94) were less likely compared to children of household-heads. LLIN use was more common in children whose mother opined that only weak children could die from malaria (AOR = 1.83, CI: 1.10-3.10). Children whose mothers obtained net from antenatal or immunisation clinics (AOR = 5.30, CI: 2.32-12.14) and campaigns (AOR = 1.77, CI: 1.03-3.04) were also more likely to use LLIN. In contrast, LLIN utilisation was less likely among children in female-headed households (AOR = 0.51, CI: 0.27-0.99) and those in poor-quality houses (AOR = 0.25, CI: 0.09-0.72). Children aged 24-59 months compared to 0-11 months (AOR = 1.78, CI: 1.28-2.48), those in whom fever was reported (AOR = 1.31, CI: 1.06-1.63) and children of uneducated women (AOR = 1.89, CI: 1.32-2.70) were more likely to have parasitaemia. The likelihood of parasitaemia was higher among children from poor households compared to the rich (AOR = 2.06, CI: 1.24-3.42). The odds of parasitaemia were 98% higher among rural children (AOR = 1.98, CI: 1.37-2.87).

CONCLUSION

The key drivers of LLIN utilisation were source of net and socioeconomic characteristics. The latter was also a key factor associated with parasitaemia. These should be targeted as part of integrated malaria elimination efforts.

Factors contributing to household wealth inequality in under-five deaths in low- and middle-income countries: decomposition analysis

BACKGROUND

The burden of under-5 deaths is disproportionately high among poor households relative to economically viable ones in developing countries. Despite this, the factors driving this inequality has not been well explored. This study decomposed the contributions of the factors associated with wealth inequalities in under-5 deaths in low- and middle-income countries (LMICs).

METHODS

We analysed data of 856,987 children from 66,495 neighbourhoods across 59 LMICs spanning recent Demographic and Health Surveys (2010-2018). Under-5 mortality was described as deaths among live births within 0 to 59 months of birth and it was treated as a dichotomous variable (dead or alive). The prevalence of under-five deaths was stratified using household wealth status. A Fairlie decomposition analysis was utilized to investigate the relative contribution of the factors associated with household wealth inequality in under-5 deaths at p<0.05. The WHO health equity assessment toolkit Plus was used to assess the differences (D) ratios (R), population attributable risk (PAR), and population attributable fraction (PAF) in household wealth inequalities across the countries.

RESULTS

The proportion of children from poor households was 45%. The prevalence of under-5 deaths in all samples was 51 per 1000 children, with 60 per 1000 and 44 per 1000 among children from poor and non-poor households (p<0.001). The prevalence of under-5 deaths was higher among children from poor households than those from non-poor households in all countries except in Ethiopia, Tanzania, Zambia, Lesotho, Gambia and Sierra Leone, and in the Maldives. Thirty-four of the 59 countries showed significantly higher under-5 deaths in poor households than in non-poor households (pro-non-poor inequality) and no significant pro-poor inequality. Rural-urban contexts, maternal education, neighborhood socioeconomic status, sex of the child, toilet kinds, birth weight and preceding birth intervals, and sources of drinking water are the most significant drivers of pro-poor inequities in under-5 deaths in these countries.

CONCLUSIONS

Individual-level and neighbourhood-level factors were associated with a high prevalence of under-5 deaths among poor households in LMICs. Interventions in countries should focus on reducing the gap between the poor and the rich as well as improve the education and livelihood of disadvantaged people.

Role of Information Sources in Vaccination Uptake: Insights From a Cross-Sectional Household Survey in Sierra Leone, 2019

Our findings suggest that health workers and faith leaders are important sources of information to deliver vaccination messages, given their strong association with vaccination confidence and uptake. In this context, vaccination promotion efforts that integrate faith leaders and health workers may help increase vaccination uptake.

Introduction:

There is limited understanding of the potential impact of information sources on vaccination attitudes and behaviors in low-income countries. We examined how exposure to immunization information sources may be associated with vaccination uptake in Sierra Leone.

Methods:

In 2019, a household survey was conducted using multistage cluster sampling to randomly select 621 caregivers of children aged 12–23 months in 4 districts in Sierra Leone. We measured exposure to various sources of immunization information and 2 outcomes: (1) vaccination confidence using an aggregate score (from 12 Likert items, informed by previously validated scale) that was dichotomized into a binary variable; (2) uptake of the third dose of diphtheria-pertussis-tetanus-hepatitis B-Haemophilus influenzae type-b-pentavalent vaccine (penta-3) based on card record or through caregiver recall when card was unavailable. Associations between information sources and the outcomes were examined using modified Poisson regression with robust variance estimator.

Results:

Weighted estimate for penta-3 uptake was 81% (75.2%–85.5%). The likelihood of uptake of penta-3 was significantly greater when caregiver received information from health facilities (adjusted prevalence ratio [aPR]=1.26, 95% confidence interval [CI]=1.1, 1.5), faith leaders (aPR=1.16, 95% CI=1.1, 1.3), and community health workers (aPR=1.13, 95% CI=1.003, 1.3). Exposure to greater number of information sources was associated with high penta-3 uptake (aPR=1.05, 95% CI=1.02, 1.1).

Discussion:

Immunization information received during health facility visits and through engagement with religious leaders may enhance vaccination uptake. Assessments to understand context-specific information dynamics should be prioritized in optimizing immunization outcomes.

Added Value of Electronic Immunization Registries in Low- and Middle-Income Countries: Observational Case Study in Tanzania

Background

There is growing interest and investment in electronic immunization registries (EIRs) in low- and middle-income countries. EIRs provide ready access to patient- and aggregate-level service delivery data that can be used to improve patient care, identify spatiotemporal trends in vaccination coverage and dropout, inform resource allocation and program operations, and target quality improvement measures. The Government of Tanzania introduced the Tanzania Immunization Registry (TImR) in 2017, and the system has since been rolled out in 3736 facilities in 15 regions.

Objective

The aims of this study are to conceptualize the additional ways in which EIRs can add value to immunization programs (beyond measuring vaccine coverage) and assess the potential value-add using EIR data from Tanzania as a case study.

Methods

This study comprised 2 sequential phases. First, a comprehensive list of ways EIRs can potentially add value to immunization programs was developed through stakeholder interviews. Second, the added value was evaluated using descriptive and regression analyses of TImR data for a prioritized subset of program needs.

Results

The analysis areas prioritized through stakeholder interviews were population movement, missed opportunities for vaccination (MOVs), continuum of care, and continuous quality improvement. The included TImR data comprised 958,870 visits for 559,542 patients from 2359 health facilities. Our analyses revealed that few patients sought care outside their assigned facility (44,733/810,568, 5.52% of applicable visits); however, this varied by region; facility urbanicity, type, ownership, patient volume, and duration of TImR system use; density of facilities in the immediate area; and patient age. Analyses further showed that MOVs were highest among children aged <12 months (215,576/831,018, 25.94% of visits included an MOV and were applicable visits); however, there were few significant differences based on other individual or facility characteristics. Nearly half (133,337/294,464, 45.28%) of the children aged 12 to 35 months were fully vaccinated or had received all doses except measles-containing vaccine–1 of the 14-dose under-12-month schedule (ie, through measles-containing vaccine–1), and facility and patient characteristics associated with dropout varied by vaccine. The continuous quality improvement analysis showed that most quality issues (eg, MOVs) were concentrated in <10% of facilities, indicating the potential for EIRs to target quality improvement efforts.

Conclusions

EIRs have the potential to add value to immunization stakeholders at all levels of the health system. Individual-level electronic data can enable new analyses to understand service delivery or care-seeking patterns, potential risk factors for underimmunization, and where challenges occur. However, to achieve this potential, country programs need to leverage and strengthen the capacity to collect, analyze, interpret, and act on the data. As EIRs are introduced and scaled in low- and middle-income countries, implementers and researchers should continue to share real-world examples and build an evidence base for how EIRs can add value to immunization programs, particularly for innovative uses.

Trend and decomposition analysis of risk factors of childbirths with no one present in Nigeria, 1990-2018

OBJECTIVES

To assess the trend and decompose the determinants of delivery with no one present (NOP) at birth with an in-depth subnational analysis in Nigeria.

DESIGN

Cross-sectional.

SETTING

Nigeria, with five waves of nationally representative data in 1990, 2003, 2008, 2013 and 2018.

PARTICIPANTS

Women with at least one childbirth within 5 years preceding each wave of data collection.

PRIMARY AND SECONDARY OUTCOME MEASURES

The outcome of interest is giving birth with NOP at delivery defined as childbirth assisted by no one. Data were analysed using Χ² and multivariate decomposition analyses at a 5% significance level.

RESULTS

The prevalence of having NOP at delivery was 15% over the studied period, ranges from 27% in 1990 to 11% in 2018. Overall, the prevalence of having NOP at delivery reduced significantly by 35% and 61% within 2003-2018 and 1990-2018, respectively (p<0.001). We found wide variations in NOP across the states in Nigeria. The highest NOP practice was in Zamfara (44%), Kano (40%) and Katsina (35%); while the practice was 0.1% in Bayelsa, 0.8% in Enugu, 0.9% in Osun and 1.1% in Imo state. The decomposition analysis of the changes in having NOP at delivery showed that 85.4% and 14.6% were due to differences in women's characteristics (endowment) and effects (coefficient), respectively. The most significant contributions to the changes were the decision-maker of healthcare utilisation (49%) and women educational status (24%). Only Gombe experienced a significant increase (p<0.05) in the level of having NOP between 2003 and 2018.

CONCLUSION

A long-term decreasing secular trend of NOP at delivery was found in Nigeria. NOP is more prevalent in the northern states than in the south. Achieving zero prevalence of NOP at delivery in Nigeria would require a special focus on healthcare utilisation, enhancing maternal education and healthcare utilisation decision-making power.

A Systems-Based Framework for Immunisation System Design: Six Loops, Three Flows, Two Paradigms

Despite massive progress in vaccine coverage globally, the region of sub-Saharan Africa is lagging behind for Sustainable Development Goal 3 by 2030. Sub-national under-immunisation is part of the problem. In order to reverse the current immunisation system's (IMS) underperformance, a conceptual model is proposed that captures the complexity of IMSs in low- and middle-income countries (LMICs) and offers directions for sustainable redesign. The IMS model was constructed based on literature and stakeholder interaction in Rwanda and Kenya. The model assembles the paradigms of planned and emergency immunisation in one system and emphasises the synchronised flows of vaccinee, vaccinator and vaccine. Six feedback loops capture the main mechanisms governing the system. Sustainability and resilience are assessed based on loop dominance and dependency on exogenous factors. The diagram invites stakeholders to share their mental models and. The framework provides a systems approach for problem structuring and policy design.

Geopolitical zones differentials in intermittent preventive treatment in pregnancy (IPTp) and long lasting insecticidal nets (LLIN) utilization in Nigeria

Background

The coverage of long lasting insecticidal nets (LLIN) and intermittent preventive treatment of malaria in pregnancy (IPTp) uptake for the prevention of malaria commonly vary by geography. Many sub-Saharan Africa (SSA) countries, including Nigeria are adopting the use of LLIN and IPTp to fight malaria. Albeit, the coverage of these interventions to prevent malaria across geographical divisions have been understudied in many countries. In this study, we aimed to explore the differentials in LLIN and IPTp uptake across Nigerian geopolitical zones.

Methods

We analyzed data from Nigeria Multiple Indicator Cluster Survey (MICS) 2016–17. The outcome variables were IPTp and LLIN uptake among women of childbearing age (15–49 years). A total sample of 24,344 women who had given birth were examined for IPTp use and 36,176 women for LLIN use. Percentages, Chi-square test and multivariable logit models plots were used to examine the geopolitical zones differentials in IPTp and LLIN utilization. Data was analyzed at 5% level of significance.

Results

The overall prevalence of IPTp was 76.0% in Nigeria. Moreover, there were differences across geopolitical zones: North Central (71.3%), North East (76.9%), North West (78.2%), South East (76.1%), South South (79.7%) and South West (72.4%) respectively. Furthermore, the prevalence of LLIN was 87.7%% in Nigeria. Also, there were differences across geopolitical zones: North Central (89.1%), North East (91.8%), North West (90.0%), South East (77.3%), South South (81.1%) and South West (69.8%) respectively. Women who have access to media use, married, educated and non-poor were more likely to uptake IPTp. On the other hand, rural dwellers and those with media use were more likely to use LLIN. Conversely, married, educated, non-poor and women aged 25–34 and 35+ were less likely to use LLIN.

Conclusion

Though the utilization of IPTp and LLIN was relatively high, full coverage are yet to be achieved. There was geopolitical zones differentials in the prevalence of IPTp and LLIN in Nigeria. Promoting the utilization of IPTp and LLINs across the six geopolitical zones through intensive health education and widespread mass media campaigns will help to achieve the full scale IPTp and LLIN utilization.

Missed opportunities for vaccination in Africa

The purpose of this review is to assess the extent of missed opportunities for vaccination (MOV) in Africa, determine the associated factors, and provide recommendations that countries could adopt in reducing MOV. Two databases were searched for multinational studies and systematic reviews reporting MOV and involving African countries. A total of 288 records were identified and 12 studies included for synthesis. The prevalence ranged from 47.0% to 62.1%, with a weighted mean of 27.3%. This review highlighted caregiver utilization, health service delivery, and healthcare worker' factors associated with MOV. Understanding the extent of MOV in Africa presents an opportunity for multiple approaches to resolve the differential factors that contribute to MOV, and to bridge the gap in vaccination coverage in the continent.

Decomposition analysis of the compositional and contextual factors associated with poor-non-poor inequality in diarrhoea among under-five children in low- and middle-income countries

OBJECTIVES

The aim of the study was to assess the magnitude of wealth inequalities in the development of diarrhoea among under-five children in low- and middle-income countries (LMICs) and to identify and quantify contextual and compositional factors' contribution to the inequalities.

DESIGN

This is a cross-sectional study.

METHODS

We used cross-sectional data from 57 Demographic and Health Surveys conducted between 2010 and 2018 in LMICs. Descriptive statistics were used to understand the gap in having diarrhoea between the children from poor and non-poor households and across the selected covariates using Fairlie decomposition techniques with multivariable binary logistic regressions at P = 0.05.

RESULTS

Of the 57 countries, we found a statistically significant pro-poor odds ratio in only 29 countries, 7 countries showed pro-non-poor inequality and others showed no statistically significant inequality. Among the countries with statistically significant pro-poor inequality, the risk difference was largest in Cameroon (94.61/1000), whereas the largest pro-non-poor risk difference in diarrhoea was widest in Timor-Leste (-41.80/1000). Important factors responsible for pro-poor inequality varied across countries. The largest contributors to the pro-poor inequalities in having diarrhoea are maternal education, access to media, neighbourhood socio-economic status, place of residence, birth order and maternal age.

CONCLUSION

Diarrhoea remains a major challenge in most LMICs, with a wide range of pro-poor inequalities. These disparities were explained by both compositional and contextual factors, which varied widely across the countries. Thus, multifaceted geographically specific economic alleviation intervention may prove to be a potent approach for addressing the poor and non-poor differentials in the risk of diarrhoea with policies tailored to country-specific risk factors. There is a need for further investigation of factors that drive pro-non-poor inequalities found in 9 of the LMICs.

Religion and Measles Vaccination in Indonesia, 1991-2017

INTRODUCTION

Some Muslim religious councils in Indonesia have ruled that measles vaccines contain haram (i.e., forbidden materials). This study evaluates the changes in measles vaccination coverage between 1991 and 2017 and compares vaccination coverage between Muslims and non-Muslims in Indonesia.

METHODS

A total of 7 cross-sectional in-person surveys of mothers in 1991-2017 in Indonesia were analyzed in 2019. Participants were asked about religion in 1991-2007, and 100 data sets of religion were imputed for 2012 and 2017. In this multiple imputation analysis, binomial regression models output prevalence differences adjusted for wealth, education, child's sex, and mother's age. A quadratic term for year (year X year) and an interaction term between year and religion evaluated changes in vaccination over time by religion.

RESULTS

The 7 data sets included 23,106 children aged 12-23 months, with the proportion of those who were Muslims ranging between 85% and 89% across the survey years. Between 1991 and 2017, measles vaccination coverage increased from 57% to 79% among non-Muslims and from 59% to 79% among Muslims. In the multivariable regression model, measles vaccination coverage increased by 1.6% each year (with a quadratic term of -0.05%, indicating some leveling over time). At baseline in 1991, non-Muslims had a vaccination coverage of 6.2% higher than that of Muslims, but this disparity decreased by -0.2% each year.

CONCLUSIONS

Measles vaccination increased in both Muslims and non-Muslims in Indonesia but has stagnated in recent years. Because of increased attention among Muslim groups on haram materials in vaccines since 2017, future studies should continue to examine the relationship between religion and vaccine uptake in Indonesia.

SUPPLEMENT INFORMATION

This article is part of a supplement entitled Global Vaccination Equity, which is sponsored by the Global Institute for Vaccine Equity at the University of Michigan School of Public Health.

The Magnitude and Determinants of Missed Opportunities for Childhood Vaccination in South Africa

Missed opportunities for vaccination (MOV) may be among the factors responsible for suboptimal vaccination coverage in South Africa. However, the magnitude and determinants of MOV in the country are not known. Thus, this study seeks to assess the prevalence and determinants of MOV in the country. South Africa is sub-divided into nine administrative provinces. We used nationally representative data from the 2016 South African Demographic and Health Survey. We considered MOV to have occurred if a child aged 12–23 months old had not taken all scheduled basic vaccine doses despite having any of the following contacts with health services: delivery in a health facility; postnatal clinic visit; receipt of vitamin A; and any child-related treatment at a health facility. Multilevel logistic regression was used to determine factors associated with MOV. The national prevalence of MOV among children aged 12–23 months was 40.1%. Children whose mothers attended facility-based antenatal care were considerably less likely to experience MOV than those whose mothers did not attend antenatal care: odds ratio (OR) 0.41, 95% confidence interval (CI) 0.19 to 0.88. Conversely, the independent predictor of an increased MOV among children was residence in either the Gauteng province (OR 2.97, 95% CI 1.29 to 6.81) or Mpumalanga province (OR 2.32, 95%CI 1.04 to 5.18); compared to residence in the Free State province. Our findings suggest a high burden of MOV among children in South Africa and that MOV may be associated with individual and contextual factors. The findings also underscore the need for further exploration of the contextual factors contributing to MOV in South Africa.

Mind the gap: What explains the poor-non-poor inequalities in severe wasting among under-five children in low- and middle-income countries? Compositional and structural characteristics

A good understanding of the poor-non-poor gap in childhood development of severe wasting (SW) is a must in tackling the age-long critical challenge to health outcomes of vulnerable children in low- and middle-income countries (LMICs). There is a dearth of information about the factors explaining differentials in wealth inequalities in the distribution of SW in LMICs. This study is aimed at quantifying the contributions of demographic, contextual and proximate factors in explaining the poor-non-poor gap in SW in LMICs. We pooled successive secondary data from the Demographic and Health Survey conducted between 2010 and 2018 in LMICs. The final data consist of 532,680 under-five children nested within 55,823 neighbourhoods from 51 LMICs. Our outcome variable is having SW or not among under-five children. Oaxaca-Blinder decomposition was used to decipher poor-non-poor gap in the determinants of SW. Children from poor households ranged from 37.5% in Egypt to 52.1% in Myanmar. The overall prevalence of SW among children from poor households was 5.3% compared with 4.2% among those from non-poor households. Twenty-one countries had statistically significant pro-poor inequality (i.e. SW concentrated among children from poor households) while only three countries showed statistically significant pro-non-poor inequality. There were variations in the important factors responsible for the wealth inequalities across the countries. The major contributors to wealth inequalities in SW include neighbourhood socioeconomic status, media access, as well as maternal age and education. Socio-economic factors created the widest gaps in the inequalities between the children from poor and non-poor households in developing SW. A potential strategy to alleviate the burden of SW is to reduce wealth inequalities among mothers in the low- and middle-income countries through multi-sectoral and country-specific interventions with considerations for the factors identified in this study.

Parental concerns and uptake of childhood vaccines in rural Tanzania - a mixed methods study

BACKGROUND

Vaccine hesitancy has been recognized as an important barrier to timely vaccinations around the world, including in sub-Saharan Africa. In Tanzania, 1 in 4 children is not fully vaccinated. The objective of this mixed methods study was to describe and contextualize parental concerns towards vaccines in Tanzania.

METHODS

Between 2016 and 2017, we conducted a cross-sectional survey (n = 134) and four focus group discussions (FGDs, n = 38) with mothers of children under 2 years of age residing in Mtwara region in Southern Tanzania. The survey and FGDs assessed vaccination knowledge and concerns and barriers to timely vaccinations. Vaccination information was obtained from government-issued vaccination cards.

RESULTS

In the cross-sectional survey, 72% of mothers reported missed or delayed receipt of vaccines for their child. Although vaccine coverage was high, timeliness of vaccinations was lower and varied by vaccine. Rural mothers reported more vaccine-related concerns compared to urban mothers; literacy and access to information were identified as key drivers of the difference. Mothers participating in FGDs indicated high perceived risk of vaccine-preventable illnesses, but expressed concerns related to poor geographic accessibility, unreliability of services, and missed opportunities for vaccinations resulting from provider efforts to minimize vaccine wastage.

CONCLUSIONS

Findings from our cross-sectional survey indicate the presence of vaccination delays and maternal concerns related to childhood vaccines in Tanzania. In FGDs, mothers raised issues related to convenience more often than issues related to vaccine confidence or complacency. Further research is necessary to understand how these issues may contribute to the emergence and persistence of vaccine hesitancy and to identify effective mitigation strategies.

Assessment of missed opportunities for vaccination in Kenyan health facilities, 2016

Background

In November 2016, the Kenya National Vaccines and Immunization Programme conducted an assessment of missed opportunities for vaccination (MOV) using the World Health Organization (WHO) MOV methodology. A MOV includes any contact with health services during which an eligible individual does not receive all the vaccine doses for which he or she is eligible.

Methods

The MOV assessment in Kenya was conducted in 10 geographically diverse counties, comprising exit interviews with caregivers and knowledge, attitudes, and practices (KAP) surveys with health workers. On the survey dates, which covered a 4-day period in November 2016, all health workers and caregivers visiting the selected health facilities with children <24 months of age were eligible to participate. Health facilities (n = 4 per county) were purposively selected by size, location, ownership, and performance. We calculated the proportion of MOV among children eligible for vaccination and with documented vaccination histories (i.e., from a home-based record or health facility register), and stratified MOV by age and reason for visit. Timeliness of vaccine doses was also calculated.

Results

We conducted 677 age-eligible children exit interviews and 376 health worker KAP surveys. Of the 558 children with documented vaccination histories, 33% were visiting the health facility for a vaccination visit and 67% were for other reasons. A MOV was seen in 75% (244/324) of children eligible for vaccination with documented vaccination histories, with 57% (186/324) receiving no vaccinations. This included 55% of children visiting for a vaccination visit and 93% visiting for non-vaccination visits. Timeliness for multi-dose vaccine series doses decreased with subsequent doses. Among health workers, 25% (74/291) were unable to correctly identify the national vaccination schedule for vaccines administered during the first year of life. Among health workers who reported administering vaccines as part of their daily work, 39% (55/142) reported that they did not always have the materials they needed for patients seeking immunization services, such as vaccines, syringes, and vaccination recording documents.

Conclusions

The MOV assessment in Kenya highlighted areas of improvement that could reduce MOV. The results suggest several interventions including standardizing health worker practices, implementing an orientation package for all health workers, and developing a stock management module to reduce stock-outs of vaccines and vaccination-related supplies. To improve vaccination coverage and equity in all counties in Kenya, interventions to reduce MOV should be considered as part of an overall immunization service improvement plan.

Decomposing the educational inequalities in the factors associated with severe acute malnutrition among under-five children in low- and middle-income countries

BACKGROUND

Low- and Middle-Income Countries (LMIC) have remained plagued with the burden of severe acute malnutrition (SAM). The decomposition of the educational inequalities in SAM across individual, household and neighbourhood characteristics in LMIC has not been explored. This study aims to decompose educational-related inequalities in the development of SAM among under-five children in LMIC and identify the risk factors that contribute to the inequalities.

METHODS

We pooled successive secondary data from the Demographic and Health Survey conducted between 2010 and 2018 in 51 LMIC. We analysed data of 532,680 under-five children nested within 55,823 neighbourhoods. Severe acute malnutrition was the outcome variable while the literacy status of mothers was the main exposure variable. The explanatory variables cut across the individual-, household- and neighbourhood-level factors of the mother-child pair. Oaxaca-Blinder decomposition method was used at p = 0.05.

RESULTS

The proportion of children whose mothers were not educated ranged from 0.1% in Armenia and Kyrgyz Republic to as much as 86.1% in Niger. The overall prevalence of SAM in the group of children whose mothers had no education was 5.8% compared with 4.2% among those whose mothers were educated, this varied within each country. Fourteen countries (Cameroon(p < 0.001), Chad(p < 0.001), Comoro(p = 0.047), Burkina Faso(p < 0.001), Ethiopia(p < 0.001), India(p < 0.001), Kenya(p < 0.001), Mozambique(p = 0.012), Namibia(p = 0.001), Nigeria(p < 0.001), Pakistan(p < 0.001), Senegal(p = 0.003), Togo(p = 0.013), and Timor Leste(p < 0.001) had statistically significant pro-illiterate inequality while no country showed statistically significant pro-literate inequality. We found significant differences in SAM prevalence across child's age (p < 0.001), child's sex(p < 0.001), maternal age(p = 0.001), household wealth quintile(p = 0.001), mother's access to media(p = 0.001), birth weight(p < 0.001) and neighbourhood socioeconomic status disadvantage(p < 0.001). On the average, neighbourhood socioeconomic status disadvantage, location of residence were the most important factors in most countries. Other contributors to the explanation of educational inequalities are birth weight, maternal age and toilet type.

CONCLUSIONS

SAM is prevalent in most LMIC with wide educational inequalities explained by individual, household and community-level factors. Promotion of women education should be strengthened as better education among women will close the gaps and reduce the burden of SAM generally. We recommend further studies of other determinate causes of inequalities in severe acute malnutrition in LMIC.

Qualitative insights into reasons for missed opportunities for vaccination in Kenyan health facilities

Background

In 2016, Kenya conducted a study of missed opportunities for vaccination (MOV)—when eligible children have contact with the health system but are not fully vaccinated—to explore some of the reasons for persistent low vaccination coverage. This paper details the qualitative findings from that assessment.

Methods

Using the World Health Organization MOV methodology, teams conducted focus group discussions among caregivers and health workers and in-depth interviews of key informants in 10 counties in Kenya. Caregivers of children <24 months of age visiting the selected health facilities on the day of the assessment were requested to participate in focus group discussions. Health workers were purposively sampled to capture a broad range of perspectives. Key informants were selected based on their perceived insight on immunization services at the county, sub-county, or health facility level.

Results

Six focus group discussions with caregivers, eight focus group discussions with health workers, and 35 in-depth interviews with key informants were completed. In general, caregivers had positive attitudes toward healthcare and vaccination services, but expressed a desire for increased education surrounding vaccination. In order to standardize vaccination checks at all health facility visits, health workers and key informants emphasized the need for additional trainings for all staff members on immunization. Health workers and key informants also highlighted the negative impact of significant understaffing in health facilities, and the persistent challenge of stock-outs of vaccines and vaccination-related supplies.

Conclusions

Identified factors that could contribute to MOV include a lack of knowledge surrounding vaccination among caregivers and health workers, inadequate number of health workers, and stock-outs of vaccines or vaccination-related materials. In addition, vaccination checks outside of vaccination visits lacked consistency, leading to MOV in non-vaccinating departments. Qualitative assessments could provide a starting point for understanding and developing interventions to address MOV in other countries.

Assessing the methodological quality of systematic reviews of interventions aimed at improving vaccination coverage using AMSTAR and ROBIS checklists

Introduction: Systematic reviews (SRs) are the backbone of evidence-based health care, but no gold standard exists to assess their methodological quality. Although the AMSTAR tool is accepted for analyzing the quality of SRs, the ROBIS instrument was recently developed. This study compared the capacity of both instruments to capture the quality of SRs of interventions for improving vaccination coverage.Methods: We conducted a comprehensive literature search in the Cochrane Library and PubMed. Two reviewers independently screened the search output, assessed study eligibility, and extracted data from eligible SRs; resolving differences through consensus. We conducted Principal Component Analysis (PCA) in Stata 14 to determine similarities and differences between AMSTAR and ROBIS.Results: A total of 2322 records were identified through the search and 75 full-text publications were assessed for eligibility, of which 57 met inclusion criteria. Using AMSTAR, we found 32%, 60% and 9% of SRs to have high, moderate and low quality, respectively. With ROBIS, we judged 74%, 14% and 12% of SRs to have low, unclear and high risk of bias. PCA showed that SRs with low risk of bias in ROBIS clustered together with SRs having high-quality in AMSTAR, and SRs with high risk of bias in ROBIS clustered with low-quality SRs in AMSTAR.Conclusions: Our findings suggest that there is an association between methodological quality and risk of bias in SRs of interventions focused on improving vaccination coverage. Therefore, either AMSTAR or ROBIS checklists can be used to evaluate methodological quality of SRs in vaccinology.

Attributes influencing parental decision-making to receive the Tdap vaccine to reduce the risk of pertussis transmission to their newborn - outcome of a cross-sectional conjoint experiment in Spain and Italy

Pertussis vaccination of parents and household contacts (‘cocooning’) to protect newborn infants is an established strategy in many countries, although uptake may be low. Many aspects may influence such decision-making. We conducted a cross-sectional survey (NCT01890447) of households and other close contacts of newborns aged ≤6 months (or of expectant mothers in their last trimester) in Spain and Italy, using an adaptive discrete-choice experiment questionnaire. Aims were to assess the relative importance of attributes influencing vaccine adoption, and to estimate variation in vaccine adoption rates and the impact of cost on vaccination rates. Six hundred and fifteen participants (Spain, n = 313; Italy, n = 302) completed the survey. Of 144 available questionnaire scenarios, the most frequently selected (14% of respondents in both countries) were infant protection by household vaccination at vaccination center, recommendation by family physician and health authorities, with information available on leaflets and websites. The attribute with highest median relative importance was ‘reduction in source of infection’ in Spain (23.1%) and ‘vaccination location’ in Italy (18.8%). Differences between other attributes were low in both countries, with media attributes showing low importance. Over 80% of respondents indicated a definite or probable response to vaccine adoption (at no-cost) with estimated probability of adoption of 89–98%; applying vaccine costs (25€ per person) would reduce the probability of uptake by 7–20% in definite/probable respondents. Awareness of these determinants is helpful in informing Health Authorities and healthcare practitioners implementing a cocooning strategy for those populations where maternal immunization is not a preferred option.

Special focus on challenges and opportunities for the development and use of vaccines in Africa

Immunization of children against vaccine-preventable diseases is one of the most cost-effective and potentially equitable public health interventions. Nevertheless, approximately 19.9 million of the world's annual birth cohort are either under-immunized or have not been vaccinated at all. Understanding the factors contributing to under-immunization in settinsg such as sub-Saharan Africa which bears a disproportionate burden of vaccine preventable diseases is key to unlocking the full potential that vaccines offer in reducing under-5 morbidity and mortality. The series or articles in this issue of the Journal, mainly through systematic analysis of District Health Surveillance data bases from 35 countries, highlight the challenges faced in improving vaccination coverage rates in sub-Saharan Africa which has stagnated at approximately 72% for completion of the primary series of infant vaccines over the past decade. The reasons for under-immunization of children is sub-Saharan Africa is identified to be multi-factorial and may differ between and within countries. This highlights the need for country-specific, possibly at a district or sub-regional level, interrogation of factors contributing to under-immunization of children, to work toward providing Universal Health Coverage as envisioned in the Sustainable Development Goals.