Evaluating the Impact of the Malaria Vaccine Rollout on Malaria Morbidity Among Under-Five Children in Phase 1 MVIP Districts in Oti Region, Ghana

Abstract

Background: Sub-Saharan African (SSA) countries remain disproportionately affected by malaria. To address the persistently high incidence, novel therapeutic interventions, such as the malaria vaccine, have been introduced in four pilot countries in SSA, including Ghana. Objective: This study evaluated the impact of the malaria vaccine rollout on malaria incidence among children under five years of age in Phase 1 Malaria Vaccine Implementation Programme districts in the Oti Region. Methods: A retrospective analysis was conducted using secondary data extracted from DHIMS2 for 2015–2024. Descriptive analyses assessed trends in confirmed malaria incidence and RTS, S vaccine coverage, while inferential analyses evaluated the impact of vaccine rollout and the association between vaccine coverage and malaria morbidity. Statistical significance was set at p < 0.05. Results: Across the study period, the intervention districts recorded a mean malaria incidence of 367 cases per 1,000 children under five years. Malaria incidence decreased significantly following the introduction of the RTS, S vaccine, with a mean reduction of 180.4 cases per 1,000 (t (8) = 5.828, p < 0.001). RTS, S coverage increased gradually from 2019 to 2024, with fourth-dose coverage rising from 0% to 20%. A strong negative association was observed between fourth-dose RTS, S coverage and malaria incidence; each unit increase in coverage was associated with a 9.31-point reduction in malaria incidence (β = −0.83, p = 0.04), explaining 69% of the variance. Conclusion: The rollout of the RTS, S vaccine was associated with a significant decline in malaria incidence among children under five years in Phase 1 MVIP districts. Despite this decline, overall vaccine coverage remained suboptimal, limiting progress towards national and global malaria reduction targets. Strengthening vaccine delivery, addressing coverage gaps, and extending programme reach are critical to sustaining and amplifying the vaccine’s potential impact.