Malaria Vaccine: Knowledge, Acceptance and Barriers Among Mothers of Under- Five Children in Owerri, Nigeria: A Cross-Sectional Study

Abstract Background Malaria remains a leading cause of childhood morbidity and mortality in sub-Saharan Africa, with Nigeria bearing the highest global burden. The phased introduction of the R21/Matrix-M malaria vaccine into Nigeria's routine immunization program since December 2024 necessitates data on knowledge, awareness, and acceptance to guide effective rollout strategies. This study assessed these parameters among mothers of under-five children in Owerri, Imo State, and identified associated sociodemographic factors. Methods A descriptive cross-sectional study was conducted among 311 mothers of children aged five years and below attending Federal Teaching Hospital Owerri, Nigeria. Data were collected using a structured, pretested, interviewer-administered questionnaire and analyzed with IBM SPSS version 27 using descriptive statistics, chi-square tests, Cramér's V, and the Mann-Whitney U test. Statistical significance was set at p < 0.05. Results The mean maternal age was 33.1 ± 6.8 years; 196(63.0%) held tertiary qualifications. Good vaccine knowledge (score ≥ 3/5) was demonstrated by 265(85.2%) of mothers; however, only 136(43.7%) correctly identified the intramuscular route of administration. Vaccine awareness was reported by 140(45.0%), with health facilities as the dominant source of information reported by 98 (70.0%)mothers. Willingness to vaccinate was high at 285(91.6%), driven primarily by the desire to prevent serious malaria illness,238 (83.5%). Among the 26 (8.4%) mothers who declined, the requirement for spousal permission was the foremost barrier documented by the mothers, at 23 (88.5%), followed by concerns about inadequate vaccine testing at 16 (61.5%). Socioeconomic class was significantly associated with both knowledge (p = 0.048) and awareness (p = 0.002); maternal education was significantly associated with awareness (p = 0.004). No sociodemographic variable significantly predicted acceptance. Conclusion High knowledge and near-universal acceptance coexist with low awareness, reflecting the pre-rollout phase in Imo State. Spousal gatekeeping and vaccine safety concerns are the principal barriers. Targeted facility-based communication, systematic male partner engagement and sustained multi-platform community mobilisation are critical for translating population-level acceptance into actual vaccine uptake. Nigeria's rollout expansion should incorporate documented lessons from the Malaria Vaccine Implementation Programme in Ghana, Kenya and Malawi, particularly regarding community pre-engagement and health worker training.