SENEGAL VACCINE DELIVERY NARRATIVE

Introduction: Exemplars in Global Health

Exemplars in Global Health aims to help public health decision makers around the world identify and implement proven strategies to improve health for people in lower- and middle-income countries (LMICs). The Exemplars program analyzes countries that have made extraordinary progress in attaining important health outcomes in spite of their resource limitations. Our hypothesis is that the lessons contained in this growing list of data-driven narratives will be a resource to government officials, researchers, entrepreneurs, nonprofit leaders, and others committed to improving health within their own countries.

In selecting Exemplar countries, we review data from within an identified time horizon to pinpoint nations that outperformed peers in key areas of public health, controlling for factors like economic growth. We seek countries from a variety of regions, to draw lessons that are relevant to many different contexts. We then work with research partners and technical advisors to understand the drivers of their success.

This narrative explores success in early-childhood immunization. The Exemplars in Global Health program has identified a set of countries that have made notable progress in achieving high vaccination coverage. This report describes the drivers of success in one of those nations, Senegal, and identifies strategies that may be applicable elsewhere.

As highlighted by the Immunization Agenda 2030, vaccines are among the greatest public health tools in human history and are essential in any primary health care system.¹ High levels of vaccination coverage—defined as the proportion of the target population who have received recommended vaccines—are necessary to control or eliminate vaccine-preventable diseases within a population.

Achieving and sustaining high coverage requires financial investment, but the return on investment may be unparalleled: for each dollar spent on routine and supplementary vaccinations in LMICs over the period of 2011–2020, the average country-level return on investment is estimated to be 51 times the cost.²

Many potential benchmarks could be used to identify Exemplar countries and assess the quality of their childhood vaccination programs. We have focused on the first and third doses of diphtheria-tetanus-pertussis-containing vaccine (abbreviated as DTP1 and DTP3) as proxies for the overall childhood vaccine delivery system.

DTP1, administered to infants at six weeks of age, is an indicator of success in introducing parents and children to a vaccination program. DTP3, which is given at 14 weeks, reflects retention in vaccine programs.

The World Health Assembly has endorsed a goal of 90% DTP3 coverage at the national level, with coverage rates no lower than 80% within any individual province, state, department, or other major subnational unit. The subnational target emphasizes that equity is essential everywhere, even in regions that are especially remote, impoverished, or unstable.³

While many countries have made significant progress toward achieving these targets, the World Health Organization (WHO)/UNICEF Estimates of National Immunization Coverage (WUENIC) show that progress has fallen short. In 2019, nearly two-thirds of countries met the target of 90% DTP3 coverage. In 2018, only one-third of countries met targets for both coverage and equity.⁴ Worldwide DTP3 coverage reached 84% in 2011. That figure remained nearly stagnant until 2020, when the COVID-19 pandemic caused sharp declines in vaccine coverage in many settings.⁵

Although the essential components of a successful vaccine delivery system are widely known, the current literature does not fully describe how and why these strategies are effective. Health officials in resource constrained LMICs must make the most effective use of limited resources. A clear understanding of how similarly comparable countries succeeded in their own programs can be a highly valuable resource for making implementation decisions.