Spatial variation and determinants of hepatitis B birth dose vaccination in Nigeria: a population-based study

Hepatitis B virus (HBV) infection remains a major public health problem in Nigeria, with an estimated prevalence of 5–10%, with a sub-Saharan African regional average of approximately 6.1%. Timely administration of the hepatitis B birth dose (HepB-BD) is essential for preventing vertical transmission and its long-term complications; however, national coverage remains below recommended targets. Despite its importance, evidence on the geographic distribution and contextual determinants of HepB-BD uptake across Nigerian states is limited. This study examined the spatial variation and determinants of HepB-BD vaccination in Nigeria. A population-based cross-sectional study that analysed data from the 2018 Nigeria Demographic and Health Survey. Spatial analysis using Local Moran’s I was performed to detect clusters of high and low HepB-BD vaccination coverage across Nigeria. Using STATA 14, binary logistic regression was used to analyse data of 13,064 children aged 0–24 months to identify predictors of Hep-B-BD vaccination. Overall, 52% of children received HepB-BD, with significant regional variation. Children of mothers with secondary or higher education, compared with those with no education, had higher odds of vaccination (aOR: 1.92; 95% CI: 1.63–2.27). Similarly, children from the richest households, relative to the poorest, had higher odds of vaccination (aOR: 2.46; 95% CI: 1.88–3.23). Antenatal care attendance, compared with none (aOR: 2.76; 95% CI: 2.39–3.18), and health facility delivery, compared with home delivery (aOR: 2.09; 95% CI: 1.83–2.38), were also associated with higher odds of vaccination. Children in the North-East (aOR: 0.68; 95% CI: 0.55–0.84) and North-West (aOR: 0.64; 95% CI: 0.51–0.80), compared with North Central, had reduced odds. Spatial analysis revealed significant clustering, with cold spots concentrated in northern Nigeria, and global spatial autocorrelation confirmed this (Moran’s I = 0.220, p = 0.001). HepB-BD coverage remains suboptimal and geographically clustered, with disparities associated with maternal, socioeconomic, and regional factors. Targeted, context-specific strategies may be required to improve equitable uptake across low-coverage states.