Spatiotemporal distribution and determinants of immunization among children aged 12–23 months in Ethiopia: Using EDHS 2000, 2005, 2011, and 2016

Globally, childhood immunization remains a major public health concern, with 19.4 million children not fully vaccinated in 2018, the majority from low- and middle-income countries. Ethiopia, in particular, reports alarmingly low immunization coverage, with nearly one million children unvaccinated and vaccine-preventable diseases accounting for approximately 16% of childhood mortality. This study aimed to examine the spatiotemporal distribution and associated factors of immunization among children aged 12-23 months in Ethiopia. Data were obtained from four rounds of the Ethiopia Demographic and Health Survey (EDHS) conducted between 2000 and 2016, comprising a sample of 6767 children. Spatial analysis was performed using ArcGIS, and statistical analysis was carried out using SAS software. The spatial partial proportional odds model was used due to the violation of the proportional odds assumption. Full immunization coverage showed a gradual increase from 14.6% in 2000 to 39.4% in 2016. Spatial clustering of immunization coverage was observed in all survey years, indicating nonrandom distribution across regions. Children born to mothers with primary education were significantly more likely to be fully vaccinated than those whose mothers had no education. The model identified several significant predictors of immunization status, including region, residence, maternal education, religion, household wealth, maternal employment, place of delivery, antenatal care, and health worker visits. A significant negative spatial auto-covariance suggested that areas with low coverage were often surrounded by higher-coverage zones. Targeted interventions, particularly in identified hotspot areas, and increased public health education are recommended, along with further research using recent data.