Routine immunization coverage among children under 24 months and its determinants in Eastern and Oti regions of Ghana

Immunization is a cornerstone of public health, significantly reducing child mortality and morbidity worldwide. Despite global progress, millions of children, particularly in low- and middle-income countries (LMICs), still lack access to lifesaving vaccines. In Ghana, disparities in vaccination coverage persist, with sub-national inequities affecting the achievement of universal immunization. This study aimed to evaluate routine immunization coverage among children under two years of age in Ghana's Eastern and Oti regions, focusing on identifying gaps and informing targeted interventions to improve immunization outcomes.

A cross-sectional study was conducted using a multistage stratified sampling approach. Data were collected from 1,114 eligible children aged 24-35 months across 73 enumeration areas in 11 districts. Vaccination information was obtained from vaccination cards or caregiver recall. Descriptive statistics and binary logistic regression were used to analyze vaccination coverage and identify factors associated with full immunization. Data were weighted to account for the multistage sampling design.

Full vaccination coverage for all antigens (excluding hepatitis B) was 18.7% (95% CI: 16.5%-21.1%), with higher rates in rural 19.7% (95% CI: 16.8%-23.1%) than urban areas 17.4% (95% CI: 14.3%-21.0%). Coverage for basic antigens was 78.8% (95% CI: 76.3%-81.1%), with rural areas 82.4% (95% CI: 79.2%-85.3%) outperforming urban areas 74.4% (95% CI: 70.4%-78.0%). The Oti region had higher coverage for basic antigens 85.3% (95% CI: 81.3%-88.5%) and the national schedule 62.1% (95% CI: 52.2%-62.4%) compared to the Eastern region. In the Eastern region, older children were more likely to be fully vaccinated (aOR: 1.06, 95% CI: 1.01-1.12, p = 0.021), while in the Oti region, age (aOR: 0.96, 95% CI: 0.89-1.04) was not a significant factor.

The study highlights significant disparities in vaccination coverage between urban and rural areas and across regions. Targeted interventions are needed to address gaps in coverage, particularly in urban areas where full vaccination rates remain lower. Strengthening health systems, leveraging technology, and improving community engagement are critical steps toward achieving equitable and high vaccination coverage for all children in Ghana.