Statistical Assessment of Immunisation Coverage Among Children Under Five in Zamfara State

Childhood immunisation coverage in Zamfara State, North West Nigeria, consistently falls below national targets, creating sustained vulnerability to vaccine-preventable disease outbreaks in an already health-system-challenged environment. This study statistically assesses immunisation coverage among children aged 12 to 59 months in Zamfara State and identifies associated factors. A two-stage cluster survey following the WHO Expanded Programme on Immunisation 30-cluster methodology enrolled 390 mother-child pairs from Gusau, Maradun, and Maru local government areas. Vaccination cards and maternal recall were used to document immunisation status for eight antigens. Coverage proportions with 95 percent confidence intervals were computed. Logistic regression identified sociodemographic predictors of complete immunisation. Complete immunisation coverage was 23.8 percent (95% CI: 19.4 to 28.6 percent), substantially below the national 57 percent estimate. BCG coverage was highest at 71 percent, while measles-rubella second dose coverage was only 18 percent. Antenatal care attendance (OR 3.6, 95% CI: 2.1 to 6.2) and proximity to immunisation centre within 5 km (OR 2.8, 95% CI: 1.7 to 4.7) were the strongest positive predictors. Maternal education below secondary level was associated with significantly lower odds of complete immunisation. The study provides statistically precise coverage estimates for Zamfara State and recommends intensified outreach immunisation, health worker deployment, and mass communication campaigns tailored to the North West geopolitical zone context. Keywords: immunisation coverage, cluster survey, Zamfara State, logistic regression, vaccine-preventable disease