Magnitude of childhood immunization and its associated factors in Sub-Saharan Africa: A mixed effect count regression analysis

BACKGROUND: Childhood immunization is an important part of public health efforts to reduce morbidity and mortality from diseases that can be prevented by vaccination. Sub-Saharan Africa (SSA) has the lowest childhood immunization coverage and the highest child mortality rate in the world. Therefore, this study aimed to assess community variation in childhood immunization and to identify determinant factors associated with childhood immunization using mixed effect count regression models. METHOD: This study used data from the 2012-2022 Demographic and Health Survey (DHS), which included 195,000 children between the ages of 12 and 23 months in 33 SSA countries. A various mixed-effects count regression model were employed to identify the variables associated with the prevalence of childhood vaccination. RESULT: In SSA, the mean average childhood immunization was 5.47 (95% CI = 5.46, 5.48), with an 8.38 variance. The mixed effect zero-inflated Poisson model fit the data the best, with the lowest DIC, AIC, and BIC values. The results of the model showed that working mothers, mothers with secondary or higher education (IRR = 1.119; 95% CI: 1.114, 1.125), rich wealth status (IRR = 1.077; 95% CI: 1.073, 1.082), having a health card (IRR = 1.265; 95% CI: 1.258, 1.271), being exposed to the media (IRR = 1.082; 95%CI: 1.077, 1.086), institutional delivery (IRR = 1.168; 95% CI: 1.163, 1.174), receiving eight or more ANC visits (IRR = 1.301; 95% CI: 1.288, 1.314), receiving vitamin A (IRR = 1.350; 95% CI: 1.344, 1.355), using a contraceptive (IRR = 1.187; 95% CI: 1.182, 1.192) and receiving Postnatal Care (PNC) (IRR = 1.075; 95% CI: 1.071, 1.080), were associated with a higher incidence of childhood immunization. While children in rural areas (IRR = 0.972; 95%CI: 0.968, 0.976) had a lower prevalence of childhood vaccinations than children in urban areas. CONCLUSION: SSA had a low coverage of childhood vaccination with significant disparities among countries. Therefore, it is essential to prioritize public health initiatives that target low-income households, rural mothers, uneducated parents, and those who have not utilized maternal health care services for the sake of increasing the coverage of childhood immunizations that in turn enhances the health of children. Furthermore, it is imperative to create policies and initiatives that tackle regional and national variations in childhood immunization rates and to actively work toward their implementation.