Immunisation Coverage and Determinants of Defaulting Among Children Aged 0 to 23 Months in Niger State, North Central Nigeria

Routine immunisation remains one of the most cost-effective public health interventions for reducing childhood morbidity and mortality, yet coverage in North Central Nigeria continues to fall below national targets. This study assesses immunisation coverage and identifies determinants of vaccine default among children aged 0 to 23 months in selected local government areas of Niger State. A cross-sectional design is applied, with 330 caregivers selected through multistage sampling from health centres and community settings. Immunisation cards are reviewed where available, and structured questionnaires collect data on caregiver knowledge, distance to vaccination centres, staff availability, cold chain reliability, and reminder mechanisms. Data are analysed using SPSS with logistic regression identifying significant predictors of incomplete immunisation. The 2022 National Immunisation Coverage Survey indicates that dropout rates between first and third doses of pentavalent vaccine exceed 20 percent in Niger State, driven largely by distance and caregiver misconceptions. The Health Belief Model is applied to understand caregiver risk perception and action barriers. Findings will support the Niger State Primary Healthcare Development Agency in strengthening outreach immunisation strategies and community mobilisation. The study aligns with national goals under the Emergency Routine Immunisation Coordination Centre framework. Keywords: immunisation coverage, vaccine default, children, Niger State, North Central Nigeria.