Drivers of routine immunization coverage improvement in Africa: findings from district-level case studies

Abstract

There is limited understanding of why routine immunization (RI) coverage improves in some settings in Africa and not in others. Using a grounded theory approach, we conducted in-depth case studies to understand pathways to coverage improvement by comparing immunization programme experience in 12 districts in three countries (Ethiopia, Cameroon and Ghana). Drawing on positive deviance or assets model techniques we compared the experience of districts where diphtheria-tetanus-pertussis (DTP3)/pentavalent3 (Penta3) coverage improved with districts where DTP3/Penta3 coverage remained unchanged (or steady) over the same period, focusing on basic readiness to deliver immunization services and drivers of coverage improvement. The results informed a model for immunization coverage improvement that emphasizes the dynamics of immunization systems at district level. In all districts, whether improving or steady, we found that a set of basic RI system resources were in place from 2006 to 2010 and did not observe major differences in infrastructure. We found that the differences in coverage trends were due to factors other than basic RI system capacity or service readiness. We identified six common drivers of RI coverage performance improvement-four direct drivers and two enabling drivers-that were present in well-performing districts and weaker or absent in steady coverage districts, and map the pathways from driver to improved supply, demand and coverage. Findings emphasize the critical role of implementation strategies and the need for locally skilled managers that are capable of tailoring strategies to specific settings and community needs. The case studies are unique in their focus on the positive drivers of change and the identification of pathways to coverage improvement, an approach that should be considered in future studies and routine assessments of district-level immunization system performance.

Keywords: Africa; Cameroon; DTP3; EPI; Ethiopia; Ghana; Immunization; Penta3; case study; health system; immunization system; mixed method; performance improvement; positive deviance; vaccination.

Figure 1

Example of grounded theory development process in Ghana (Larson et al. 2012).

Figure 2

Pathway of community-centred health worker driver.

Figure 3

Pathway of health system-community partnership driver.

Figure 4

Pathway of regular review of performance driver.

Figure 5

Pathway of tailoring immunization services to community needs driver.

Figure 6

Pathway to improving routine immunization coverage at district level in Africa.