Zimbabwe’s Model of PEI-EPI Synergy and Transition Preparedness Toward Sustainable Immunization Systems: A Descriptive Case Study

Background As the Global Polio Eradication Initiative (GPEI) winds down, Integrating Polio Eradication (PEI) functions into routine immunization (RI) systems has become a global priority. The Immunization Agenda 2030 (IA2030) and the WHO Polio Transition Framework emphasise embedding polio assets within national health systems to ensure sustainability and health emergencies preparedness. While most transition analyses have focused on core GPEI countries, there is limited peer-reviewed documentation from non-priority settings. This study reviews Zimbabwe’s model of PEI–EPI synergy, examining its operational features, transition preparedness, and implications for immunization system strengthening. Methods This study was designed as a policy and operational analysis, using a descriptive qualitative case study approach based on documents review. Forty-one program documents produced between 2022 and 2025, including outbreak response plans, campaign reports, surveillance performance summaries, minutes of coordination meetings, and transition planning materials, were systematically reviewed using a structured extraction matrix. The analysis was guided by the IA2030, the WHO Polio Transition Framework, the GPEI Polio Outbreak response requirements, and best practices from peer-reviewed literature on health systems integration, with thematic content analysis applied to identify synergy mechanisms, transition enablers, and areas requiring institutionalization. Results Findings reveal a pragmatic model of operational integration: · The EPI Manager serves as National Incident Manager, and the Polio Emergency Operation Center (EOC) is established within the EPI Unit, providing unified coordination platform. · Service delivery is integrated, with nurses and Village Health Workers (VHWs) delivering both polio campaigns and RI, supported by shared planning, supportive supervision, cold chain, and logistic systems. · Community engagement relies on the country’s VHW program, a long-standing Primary Health Care (PHC) platform, with harmonized messaging for polio and RI. · Financing for campaigns flowed through WHO/UNICEF via Direct Financial Cooperation (DFC)/Direct Cash Transfer (DCT) mechanisms to Ministry of Health and Child Care (MoHCC) for government to manage funds. However, policy formalization, long-term internal financing strategies, and comprehensive transition monitoring remain underdeveloped, representing critical areas to strengthen as the country moves toward a sustainable post-GPEI immunization system and polio eradication efforts. Conclusion Zimbabwe’s model illustrates that PEI–EPI synergy can be achieved through existing national systems, offering a practical example of early transition readiness even in a non-core GPEI/Polio transition countries. By embedding polio functions in governance, service delivery, and community engagement structures, Zimbabwe avoided parallel systems and demonstrated the feasibility of functional integration. However, sustainability depends on formalizing governance, harmonizing data, securing domestic financing, and reenforcing VHW program support. These lessons contribute to global transition discourse, highlighting pragmatic pathways to achieve eradication goals while strengthening immunization systems.