Mixed-methods systematic review and meta-analysis of malaria vaccine acceptance for under-five children in Nigeria

Background,Nigeria bears the highest global malaria burden, and the ongoing national rollout of the RTS,S/AS01 and R21/Matrix-M malaria vaccines underscores the centrality of caregiver acceptance to maximizing the public health benefits of these vaccines. Here aimed to estimate the pooled prevalence of malaria vaccine acceptance and synthesised its determinants.,Methods: In this mixed-methods systematic review and meta-analysis, we searched multiple databases for studies of caregiver malaria vaccine acceptance in Nigeria. Thirty-two studies (26 cross-sectional, 5 mixed-methods, 1 qualitative; 2015–2026; all six geopolitical zones) were included. Acceptance proportions were pooled with a random-effects model using the Freeman–Tukey transformation while heterogeneity, subgroup, sensitivity and publication-bias analyses were performed, and determinants and qualitative themes were integrated.,Results: Across 28 studies (N=13,211), pooled acceptance was 91.0% (95% CI 87.0–94.0), with very high heterogeneity (I²=97.8%). The estimate was robust in sensitivity analyses restricted to higher-quality, probability-sampled studies (90.0–92.0%) and did not differ by vaccine type (p=0.42). Acceptance varied by geopolitical zone (North-Central [95.0%], South-East [94.0%], North-East [92.0%], South-West [91.0%], North-West [88.0%], South-South [82.0%]), and by state. It was highest pre-COVID (96.0%) and post-pandemic (91.0%), but substantially lower during the pandemic (70.0%; 2 studies). Awareness and knowledge, positive perception, prior childhood-immunisation experience, younger caregiver age and higher education were associated with higher acceptance, while fear of side-effects was the commonest barrier. Qualitatively, trust in health workers and religious or traditional leaders was the strongest facilitator, whereas household disapproval, safety rumours (infertility, government distrust) and cost or access barriers were decisive despite nominally free provision.,Conclusions: Malaria vaccine acceptance among Nigerian caregivers is high, with slight variation across settings. Translating this willingness into sustained, equitable coverage will require demand-generation through trusted messengers, closing the awareness gap, engaging household decision-makers, and ensuring free, accessible delivery.