Health systems constraints and facilitators of human papillomavirus immunization programmes in sub-Saharan Africa: a systematic review

Given the vast investments made in national immunization programmes (NIPs) and the significance of NIPs to public health, it is important to understand what influences the optimal performance of NIPs. It has been established that well-performing NIPs require enabling health systems. However, systematic evidence on how the performance of health systems impacts on NIPs is lacking, especially from sub-Saharan Africa. We conducted a qualitative systematic review to synthesize the available evidence on health systems constraints and facilitators of NIPs in sub-Saharan Africa, using human papillomavirus immunization programmes as a proxy. Fifty-four articles published between 2008 and 2018 were found to be eligible. Data extraction was guided by an analytical model on the interface between NIPs and health systems. A cross-cutting thematic analysis of the extracted data was performed. This systematic review provides evidence necessary for informing ongoing health systems strengthening initiatives in sub-Saharan Africa. There is evidence to suggest that NIPs in sub-Saharan Africa have surmounted significant health systems constraints and have achieved notable public health success. This success can be attributed to strong political endorsement for vaccines, clear governance structures and effective collaboration with global partners. Despite this, significant health systems constraints persist in service delivery, vaccine communication, community engagement, the capacity of the health workforce and sustainable financing. These constraints could derail further progress if not addressed through health systems strengthening efforts. There is a need to expand the research agenda to include the comprehensive evaluation of health systems constraints and facilitators of NIPs within sub-Saharan Africa.