Assessing the Implementation Determinants of Pilot Malaria Vaccination Programs in Ghana, Kenya, and Malawi through a Complexity Lens: A Rapid Review Using a Consolidated Framework for Implementation Research.

In 2019, national immunization programs in Ghana, Kenya, and Malawi commenced the implementation of RTS,S/AS01 vaccination in large-scale pilot schemes. Understanding the implementation context of this malaria vaccination in the pilot countries can provide useful insights for enhancing implementation outcomes in new countries. There has not yet been a proper synthesis of the implementation determinants of malaria vaccination programs. A rapid review was conducted to identify the implementation determinants of the pilot malaria vaccination programs in Ghana, Kenya, and Malawi, and describe the mechanism by which these determinants interact with each other. A literature search was conducted in November 2023 in PubMed and Google Scholar to identify those studies that described the factors affecting malaria vaccine implementation in Ghana, Kenya, and Malawi. Thirteen studies conducted between 2021 and 2023 were included. A total of 62 implementation determinants of malaria vaccination across all five domains of the consolidated framework for implementation research (CFIR) were identified. A causal loop diagram showed that these factors are interconnected and interrelated, identifying nine reinforcing loops and two balancing loops. As additional countries in Africa prepare for a malaria vaccine roll-out, it is pertinent to ensure that they have access to adequate information about the implementation context of countries that are already implementing malaria vaccination programs so that they understand the potential barriers and facilitators. This information can be used to inform context-specific systems enhancement to maximize implementation success. Going forward, primary implementation studies that incorporate the causal loop diagram should be integrated into the malaria vaccine implementation program to enable immunization program managers and other key stakeholders to identify and respond to emerging implementation barriers in a timely and systematic manner, to improve overall implementation performance.