Why is Zambia an Exemplar?

For the purposes of this study, we have defined Exemplars as countries that have proven to be positive outliers in increasing immunization coverage (using the first dose of diphtheria, tetanus, and pertussis vaccine [DTP1] and the third dose [DTP3] as proxy indicators).¹ Their success cannot be statistically attributed to economic growth, as reflected by gross national income, gross domestic product, total health spending, or levels of development assistance for health (see Figure 1).

Since the 2000s, Zambia has performed better than its economic peers in DTP3 coverage. In Figure 1, the dark gray line represents the global average relationship between the sociodemographic index (a composite measure identifying countries on a scale of development using education, total fertility rate, and income per capita) and DTP3 coverage in low- and middle-income countries.^2,3 The shaded area represents the 95% confidence interval. The observed sociodemographic index and DTP3 coverage estimates for each country are shown underlaid in light gray.

Zambia’s trajectory in vaccine delivery, shown in blue dots along with the trajectory of other Exemplar countries, shows consistently high performance in DTP3 coverage, typically outpacing other countries in similar settings.

Zambia has maintained high levels of DTP1 coverage since the early 2000s and simultaneously narrowed the gap between DTP1 and DTP3 coverage (see Figure 2). Not only was this observed at the national level but also at the district level; only six districts had achieved the 10% Global Vaccine Action Plan target in 2000, whereas the majority of districts were within this threshold in 2019, as seen in Figure 3.^4,5 Thus, Zambia was selected as an Exemplar country due to its performance over time. Its improvement in DTP3 coverage over the period from 2000 to 2019 exceeded that of its peers (see Figure 1). More information on country selection can be found in the Methodology section.

DTP3 coverage levels showed improvements nationwide in Zambia from 2000 to 2019. Variations still existed at the subnational level, however, as seen in Figure 4. Over the years, most areas experienced increases in coverage, with the central and northern regions of the country having the highest vaccination rates and the western region having the lowest as of 2019.

How did Zambia achieve these improvements? In this case study, we have taken both qualitative and quantitative approaches to generate hypotheses on the key drivers of success related to health facility readiness, intent to vaccinate, and community access within the context of governance and finance, health systems, and past and present interventions (see Figure 5).⁶

We hypothesize that several factors contributed to successful vaccine programming: strong collaboration and communication between the Zambian government, partners, and communities as well as effective coordination between the national and subnational levels.

Based on actions taken to improve Zambia’s immunization program, we propose the following recommendations for other countries aiming to improve vaccine coverage.

Enhance health facility readiness and community access by:

• Prioritizing community access as a common goal and providing the tools to monitor and evaluate programs.
• Investing in human resources and health systems infrastructure to ensure an adequate supply of materials and personnel to increase access, reliability, and convenience for community members.
• Systemizing a bottom-up approach to evidence-based decision making. Foster subnational responsibility in program planning, reporting, management, and evaluation, and build capacity for using data among workers at both national and subnational levels.
• Ensuring that vertical funding mechanisms that focus on specific issues also contribute to the strength of the overall immunization system.
• Coordinating stakeholders toward shared priorities. Improve coordination across ministries and between the government and external stakeholders toward common priorities. Use a multisectoral approach to encourage pooled resources from partners and donors.
• Adapting external strategies to the local context. Formalize structures for input and feedback from representatives at national and subnational levels to ensure that interventions and their implementation meet the needs of stakeholders and beneficiaries.

Build intent to vaccinate by:

• Involving community leaders or representatives in health programming. Work with communities to ensure priorities and programs are responsive to local needs. Engage with community leaders to build ownership and to promote immunization.
• Creating normative expectations at the community level to generate demand. Disseminate accurate and consistent information through multiple platforms to educate community members on immunization and increase intent to vaccinate.

This review builds on an extensive body of knowledge, referenced later in this narrative, about the essential components of an effective vaccine delivery system. Two guidelines synthesize this knowledge: Global Routine Immunization Strategies and Practices (GRISP) describes a comprehensive framework of strategies and practices for routine immunization.⁷ The Reaching Every District approach defines five strategies to equitably increase immunization coverage rates: (1) planning and managing resources, (2) reaching all eligible populations, (3) engaging with communities, (4) conducting supportive supervision, and (5) monitoring and using data for action.⁸ In addition, evaluations such as the Africa Routine Immunization System Essentials project and the Full Country Evaluations conducted for Gavi, the Vaccine Alliance have documented factors that contribute to coverage improvements. These assessments have also shed light on how vaccination programs are being implemented and on the various obstacles to immunization.^9,10

For more information on how Zambia achieved success in its immunization program, see the sections on What Did Zambia Do? and How Did Zambia Implement?