Spatial distribution of Zero-dose vaccination coverage and determinants of vaccination status among children aged 12-23 months in East Africa: A Bayesian hierarchical modeling approach based on DHS 2019 to 2022

Abstract

Background: Vaccines are the cornerstone of public health interventions, preventing the spread of many diseases and saving many lives. However, vaccines are still overlooked and underused in many parts of the world, particularly in East African countries, where high rates of mortality among children under the age of five are largely caused by vaccine-preventable diseases. Objectives: The general objective of this study is to assess spatial distribution of zero dose children vaccination coverage and determinant of vaccination status in East Africa using and Bayesian hierarchical modeling approach based on Demographic and Health Survey 2019 to 2022. Methods: This study utilized data from the Demographic and Health Survey, conducted across five East African countries since 2019. Data analysis was performed using R software version 4.4.1. To identify factors influencing vaccination coverage, we applied Bayesian hierarchical regression models. Four distinct Bayesian models were evaluated using leave-one-out cross validation to select the best-fitting model. After verifying algorithm convergence, statistical significance was assessed through 95% posterior credible intervals, ensuring robust inference. Results: Spatial analysis of zero dose vaccination had cluster distribution with significant spatial variation. The Bayesian hierarchical ordinal logistic regression showed that country (Kenya) [AOR = 3.10, 95% CrI: (2.49, 3.86)], media exposure (25-34) [AOR = 1.25, 95% CrI: (1.15, 1.38)], maternal education (secondary or above) [AOR =1.42, 95% CrI: (1.21, 1.67)], health facility delivery [AOR = 1.53, 95% CrI: (1.19, 1.96)], postnatal care visit [AOR = 1.28, 95% CrI: (1.15, 1.43)], skilled birth attendance [AOR = 1.61, 95% CrI: (1.24, 2.079)], and ANC visits (four and above)[AOR = 4.08, 95% CI: (3.44, 4.84)] were significant determinants of children vaccination coverage. Conclusion and Recommendations: Vaccination coverage remains low across East Africa, with significant regional disparities. These results highlight the need for focused interventions in high-risk areas and addressing key determinants to improve childhood vaccination rates. To enhance child health and ensure equitable access to vaccines, international organizations, policymakers, and health ministries in East Africa should prioritize allocating resources to these vulnerable regions