Abstract:

Immunization is a cost-effective strategy for reducing childhood morbidity and mortality, yet Nigeria faces challenges in achieving optimal vaccination coverage. This study assessed the prevalence and determinants of incomplete immunization among children aged 0–23 months in Ifelodun LGA through a cross-sectional survey of 383 caregivers selected via multistage random sampling. Data were collected using structured questionnaires and analyzed using descriptive statistics, chi-square tests, and logistic regression. While 93.5% of children received at least one vaccine, only 19.6% were fully immunized. Three immunization gaps were identified: zero-dose children (6.5%), under-immunized (50.4%), and dropouts (23.5%). Place of delivery significantly influenced coverage, with hospital-born children having higher full immunization rates (25.5%) compared to home births, which had higher dropout rates (29.6%). Key barriers included parental negligence (23.1%), lack of awareness (18.8%), fear of side effects (15.6%), and accessibility/financial constraints (12% and 11.4%). Multivariate analysis showed zero-dose status was predicted by lack of awareness (OR=3.96, p=0.053), unfamiliarity with vaccination sites (OR=11.44, p=0.014), and stockouts (OR=10.74, p=0.007). Under-immunization was strongly linked to older child age (OR=6.75, p=0.001), while learning about vaccines from friends was protective (OR=0.32, p=0.009). Dropout risk increased with older age (OR=3.93, p=0.002) but decreased with caregiver education from friends (OR=0.23, p=0.027). Despite the high initial uptake, dropout rates remain concerning. Targeted interventions addressing health system barriers, education, supply chains, and community engagement are critical to improving coverage.

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