Determinants of geographical inequalities for DTP3 vaccine coverage in sub-Saharan Africa

Examining geographical inequalities for malaria outcomes and spending on malaria in 40 malaria-endemic countries, 2010-2020

BACKGROUND

While substantial gains have been made in the fight against malaria over the past 20 years, malaria morbidity and mortality are marked by inequality. The equitable elimination of malaria within countries will be determined in part by greater spending on malaria interventions, and how those investments are allocated. This study aims to identify potential drivers of malaria outcome inequality and to demonstrate how spending through different mechanisms might lead to greater health equity.

METHODS

Using the Gini index, subnational estimates of malaria incidence and mortality rates from 2010 to 2020 were used to quantify the degree of inequality in malaria burden within countries with incidence rates above 5000 cases per 100,000 people in 2020. Estimates of Gini indices represent within-country distributions of disease burden, with high values corresponding to inequitable distributions of malaria burden within a country. Time series analyses were used to quantify associations of malaria inequality with malaria spending, controlling for country socioeconomic and population characteristics.

RESULTS

Between 2010 and 2020, varying levels of inequality in malaria burden within malaria-endemic countries was found. In 2020, values of the Gini index ranged from 0.06 to 0.73 for incidence, 0.07 to 0.73 for mortality, and 0.00 to 0.36 for case fatality. Greater total malaria spending, spending on health systems strengthening for malaria, healthcare access and quality, and national malaria incidence were associated with reductions in malaria outcomes inequality within countries. In addition, government expenditure on malaria, aggregated government and donor spending on treatment, and maternal educational attainment were also associated with changes in malaria outcome inequality among countries with the greatest malaria burden.

CONCLUSIONS

The findings from this study suggest that prioritizing health systems strengthening in malaria spending and malaria spending in general especially from governments will help to reduce inequality of the malaria burden within countries. Given heterogeneity in outcomes in countries currently fighting to control malaria, and the challenges in increasing both domestic and international funding allocated to control and eliminate malaria, the efficient targeting of limited resources is critical to attain global malaria eradication goals.

Exploring trends and determinants of basic childhood vaccination coverage: Empirical evidence over 41 years

Vaccination is widely considered to be one of the most important prevention measures as a health strategy. This paper examines trends in basic childhood vaccination coverage and which country and time-dependent determinants may have influenced childhood immunization rates (1-dose BCG, 1- and 3-dose DTP (diphtheria, tetanus, pertussis), 1-dose measles, and 3-dose polio) between 1980 and 2020 across 94 countries. We identify economic, inequality, demographic, health, education, labor market, environmental, and political stability factors of immunization. To do this, we use data from the annual WHO and United Nations International Children's Emergency Fund (UNICEF) coverage estimates. The empirical analysis consists of generalized estimating equation models to assess relationships between immunization rates and socioeconomic factors. Additionally, we follow the Barro and Sala-i-Martín approach to identify conditional convergence. Our findings show the strongest positive statistically significant association between immunization rates and GDP per capita, as well as births attended by skilled health staff. Moreover, our research demonstrates conditional convergence, indicating that countries converge towards different steady states. The present study brings new insights to investigating the determinants of childhood vaccination coverage and provides significant implications for health policies.

Assessing Vaccination Delivery Strategies for Zero-Dose and Under-Immunized Children in the Fragile Context of Somalia

Somalia is one of 20 countries in the world with the highest numbers of zero-dose children. This study aims to identify who and where zero-dose and under-vaccinated children are and what the existing vaccine delivery strategies to reach zero-dose children in Somalia are. This qualitative study was conducted in three geographically diverse regions of Somalia (rural/remote, nomadic/pastoralists, IDPs, and urban poor population), with government officials and NGO staff (n = 17), and with vaccinators and community members (n = 52). The data were analyzed using the GAVI Vaccine Alliance IRMMA framework. Nomadic populations, internally displaced persons, and populations living in remote and Al-shabaab-controlled areas are three vulnerable and neglected populations with a high proportion of zero-dose children. Despite the contextual heterogeneity of these population groups, the lack of targeted, population-specific strategies and meaningful engagement of local communities in the planning and implementation of immunization services is problematic in effectively reaching zero-dose children. This is, to our knowledge, the first study that examines vaccination strategies for zero-dose and under-vaccinated populations in the fragile context of Somalia. Evidence on populations at risk of vaccine-preventable diseases and barriers to vital vaccination services remain critical and urgent, especially in a country like Somalia with complex health system challenges.

Is health expenditure on immunisation associated with immunisation coverage in sub-Saharan Africa? A multicountry analysis, 2013-2017

OBJECTIVES

The designing of contextually tailored sustainable plans to finance the procurement of vaccines and the running of appropriate immunisation programmes are necessary to address the high burden of vaccine-preventable diseases and low immunisation coverage in sub-Saharan Africa (SSA). We sought to estimate the minimum fraction of a country's health budget that should be invested in national immunisation programmes to achieve national immunisation coverage of 80% or greater depending on the context, with and without donors' support.

DESIGN

Multicountry analysis of secondary data using retrieved publicly available data from the WHO, Global Alliance for Vaccines and Immunization (GAVI) and World Bank databases.

SETTING

Data on 24 SSA countries, between 2013 and 2017.

METHODS

We model the variations in immunisation coverage across the different SSA countries using a fractional logit model. Three different generalised linear models were fitted to explore how various explanatory variables accounted for the variability in each of the three different vaccines-measles-containing vaccine (MCV)1, diphtheria, pertussis, tetanus (DPT3) and BCG.

RESULTS

We observed an association between current health expenditure (as a percentage of gross domestic product) and immunisation coverage for BCG (OR=1.01, 95% CI: 1.01 to 1.04, p=0.008) and DPT3 (OR=1.01, 95% CI: 1.0 to 1.02, p=0.020) vaccines. However, there was no evidence to indicate that health expenditure on immunisation (as a proportion of current health expenditure) could be a strong predictor of immunisation coverage (DPT, OR 0.96 (95% CI 0.78 to 1.19; p=0.702); BCG, OR 0.91 (0.69 to 1.19; p=0.492); MCV, OR 0.91 (0.69 to 1.19; p=0.482)). We demonstrate in selected countries that to achieve the GAVI target of 80% in the countries with low DPT3 coverage, health expenditure would need to be increased by more than 45%.

CONCLUSIONS

There is a need to facilitate the development of strategies that support African countries to increase domestic financing for national immunisation programmes towards achieving 2030 targets for immunisation coverage.

Factors associated with vaccine coverage improvements in Senegal between 2005 and 2019: a quantitative retrospective analysis

OBJECTIVE

Senegal has demonstrated catalytic improvements in national coverage rates for early childhood vaccination, despite lower development assistance for childhood vaccines in Senegal compared with other low-income and lower-middle income countries. Understanding factors associated with historical changes in childhood vaccine coverage in Senegal, as well as heterogeneities across its 14 regions, can highlight effective practices that might be adapted to improve vaccine coverage elsewhere.

DESIGN

Childhood vaccination coverage rates, demographic information and health system characteristics were identified from Senegal's Demographic and Health Surveys (DHS) and Senegal national reports for years 2005-2019. Multivariate logistic and linear regression analyses were performed to determine statistical associations of demographic and health system characteristics with respect to childhood vaccination coverage rates.

SETTING

The 14 administrative regions of Senegal were chosen for analysis.

PARTICIPANTS

DHS women's survey respondents with living children aged 12-23 months for survey years 2005-2019.

OUTCOME MEASURES

Immunisation with the third dose of the diphtheria-tetanus-pertussis vaccine (DTP3), widely used as a proxy for estimating immunisation coverage levels and the retention of children in the vaccine programme.

RESULTS

Factors associated with childhood vaccination coverage include urban residence (β=0.61, p=0.0157), female literacy (β=1.11, p=0.0007), skilled prenatal care (β=1.80, p<0.0001) and self-reported ease of access to care when sick, considering travel distance to a healthcare facility (β=-0.70, p=0.0009) and concerns over travelling alone (β=-1.08, p<0.0001). Higher coverage with less variability over time was reported in urban areas near the capital and the coast (p=0.076), with increased coverage in recent years in more rural and landlocked areas.

CONCLUSIONS

Childhood vaccination was more likely among children whose mothers had higher literacy, received skilled prenatal care and had perceived ease of access to care when sick. Overall, vaccination coverage is high in Senegal and disparities in coverage between regions have decreased significantly in recent years.

Exploring the subnational inequality and heterogeneity of the impact of routine measles immunisation in Africa

Despite vaccination being one of the most effective public health interventions, there are persisting inequalities and inequities in immunisation. Understanding the differences in subnational vaccine impact can help improve delivery mechanisms and policy. We analyse subnational vaccination coverage of measles first-dose (MCV1) and estimate patterns of inequalities in impact, represented as deaths averted, across 45 countries in Africa. We also evaluate how much this impact would improve under more equitable vaccination coverage scenarios. Using coverage data for MCV1 from 2000-2019, we estimate the number of deaths averted at the first administrative level. We use the ratio of deaths averted per vaccination from two mathematical models to extrapolate the impact at a subnational level. Next, we calculate inequality for each country, measuring the spread of deaths averted across its regions, accounting for differences in population. Finally, using three more equitable vaccination coverage scenarios, we evaluate how much impact of MCV1 immunisation could improve by (1) assuming all regions in a country have at least national coverage, (2) assuming all regions have the observed maximum coverage; and (3) assuming all regions have at least 80% coverage. Our results show that progress in coverage and reducing inequality has slowed in the last decade in many African countries. Under the three scenarios, a significant number of additional deaths in children could be prevented each year; for example, under the observed maximum coverage scenario, global MCV1 coverage would improve from 76% to 90%, resulting in a further 363(95%CrI:299-482) deaths averted per 100,000 live births. This paper illustrates that estimates of the impact of MCV1 immunisation at a national level can mask subnational heterogeneity. We further show that a considerable number of deaths could be prevented by maximising equitable access in countries with high inequality when increasing the global coverage of MCV1 vaccination.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

Background

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

Methods

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

Results

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

Conclusion

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

Leaving No Child Behind: Decomposing Socioeconomic Inequalities in Child Health for India and South Africa

BACKGROUND

The United Nations' 2030 Agenda for Sustainable Development argues for the combating of health inequalities within and among countries, advocating for "leaving no one behind". However, child mortality in developing countries is still high and mainly driven by lack of immunization, food insecurity and nutritional deficiency. The confounding problem is the existence of socioeconomic inequalities among the richest and poorest. Thus, comparing South Africa's and India's Demographic and Health Surveys (DHS) of 2015/16, this study examines socioeconomic inequalities in under-five children's health and its associated factors using three child health indications: full immunization coverage, food insecurity and malnutrition.

METHODS

Erreygers Normalized concentration indices were computed to show how immunization coverage, food insecurity and malnutrition in children varied across socioeconomic groups (household wealth). Concentration curves were plotted to show the cumulative share of immunization coverage, food insecurity and malnutrition against the cumulative share of children ranked from poorest to richest. Subsequent decomposition analysis identified vital factors underpinning the observed socioeconomic inequalities.

RESULTS

The results confirm a strong socioeconomic gradient in food security and malnutrition in India and South Africa. However, while full childhood immunization in South Africa was pro-poor (-0.0236), in India, it was pro-rich (0.1640). Decomposed results reported socioeconomic status, residence, mother's education, and mother's age as primary drivers of health inequalities in full immunization, food security and nutrition among children in both countries.

CONCLUSIONS

The main drivers of the socioeconomic inequalities in both countries across the child health outcomes (full immunization, food insecurity and malnutrition) are socioeconomic status, residence, mother's education, and mother's age. In conclusion, if socioeconomic inequalities in children's health especially food insecurity and malnutrition in South Africa; food insecurity, malnutrition and immunization in India are not addressed then definitely "some under-five children will be left behind".