Vaccine introductions in the WHO African Region, 2023-26: a country-level ecological analysis by Gavi eligibility and conflict-affected status

Background. The Immunization Agenda 2030 (IA2030) tracks new and underused vaccine introduction as an access metric, and its mid-term review calls for stronger country ownership, prioritisation, data use and tailored support in conflict-affected and resource-constrained settings; however, national launch status does not measure recurrent financing, implementation, safety or equity. We examined how recent vaccine-introduction activity was distributed across the WHO African Region. Methods. We conducted a descriptive country-level ecological analysis of all 47 Member States from January 2023 to June 2026. The country was the unit of analysis and contributed one cumulative, unweighted count of nationally endorsed vaccine-introduction and programme-change events. Counts were linked to Gavi eligibility, World Bank FY26 conflict-affected status, broader fragile and conflict-affected situation status in sensitivity analysis, and concurrent system-performance indicators, and modelled with Poisson regression using HC1 robust standard errors. Two Expanded Programme on Immunization (EPI) manager survey waves were summarised at country level. Reporting followed STROBE and RECORD. Results. Seventy-two events were recorded across 38 of 47 Member States: 48 new-antigen introductions, 20 dose or schedule expansions and four combination-vaccine introductions; malaria vaccines accounted for 21. Gavi-eligible conflict-affected countries averaged 2.50 events per country versus 1.27 in both comparison groups. Gavi-eligible conflict-affected status was associated with a higher count (incidence rate ratio [IRR] 1.97, 95% confidence interval [CI] 1.38-2.81; p<0.001), whereas non-Gavi status was not (IRR 1.00, 95% CI 0.54-1.87). The association was strongest for new-antigen introductions (IRR 2.36, 95% CI 1.43-3.91), attenuated but persisted after excluding malaria-vaccine events (IRR 1.77, 95% CI 1.06-2.97), and was robust to baseline introduction-opportunity adjustment (IRR 2.00). Surveys reported constraints in prioritisation, financing, 2026 preparation and post-introduction evaluation. Conclusions. Recent vaccine-introduction activity concentrated where Gavi eligibility, conflict-affected status and weaker concurrent system performance intersected. The association attenuated after excluding malaria-vaccine events, suggesting that the observed financing-conflict gradient was not solely driven by malaria vaccine rollout. However, the ecological design supports no causal inference. Monitoring should pair launch status with financing, implementation, safety and equity indicators to distinguish policy adoption from sustained protection.