Abstract
BACKGROUND: Childhood immunization is crucial for reducing morbidity and mortality from vaccine-preventable diseases. Despite global efforts, Nigeria faces persistently low immunization uptake with significant regional and socioeconomic disparities. This study investigated the prevalence, regional disparities, and sociodemographic determinants of full immunization coverage among children aged 12-23 months in Nigeria. METHODS: This secondary analysis utilized data from the 2018 Nigeria Demographic and Health Survey (NDHS), focusing on 2453 mothers with children aged 12-23 months. Full immunization coverage was defined per World Health Organization (WHO) guidelines. Descriptive statistics, bivariate analysis, and multivariable logistic regression identified predictors of coverage. RESULTS: Only 26% of children were fully immunized nationwide. Marked regional disparities were observed, with the North West (13%) and North East (18%) exhibiting the lowest rates, while the South East (42%) and South South (41%) had the highest. Multivariable analysis revealed that maternal education, household wealth, and region of residence were significant predictors. Children of mothers with higher education were more likely to be fully immunized (AOR: 1.87, 95% CI: 1.10-3.18, p = 0.022), as were those from the richest households compared to the poorest (AOR: 3.20, 95% CI: 1.95-5.25, p < 0.001). Children in the South East (AOR: 2.00, 95% CI: 1.16-3.46, p = 0.013) and South South (AOR: 1.73, 95% CI: 0.99-3.02, p = 0.052) also showed significantly higher odds of full immunization compared to the North West. CONCLUSION: Full immunization coverage in Nigeria remains critically low, driven by pronounced regional and socioeconomic inequities. Targeted interventions focusing on improving maternal education, expanding equitable healthcare access in underserved regions, and providing financial support to low-income families are essential. Policy efforts must prioritize these vulnerable groups to enhance child health outcomes and achieve universal immunization coverage in Nigeria.