Prevalence and its associated factors of zero-dose vaccination and barriers among children under the age of 2 years in Southwest Ethiopia: A mixed-method study.

Introduction: Vaccination significantly reduces morbidity and mortality among children from vaccine-preventable diseases. Despite a global and regional immunization coverage estimate of 74%, Ethiopia has ~1,146,000 zero-dose children. Therefore, this study estimated the prevalence of zero-dose vaccination and identified factors and barriers among children under 2 years of age in South West Ethiopia. Method: An explanatory sequential mixed-methods design was employed; the quantitative component consisted of a community-based cross-sectional study, and the qualitative component was assessed using a qualitative descriptive approach through in-depth interviews. Following data cleansing, the status of the first dose of the pentavalent vaccination was classified as either "vaccinated for first dose of the pentavalent vaccine" or "not vaccinated for first dose of the pentavalent vaccine." Then, associated factors of being zero-dose at Result: The results indicated that 17% of children were zero-dose, and lack of antenatal care visit (adjusted odds ratio = 4.005; 95% confidence interval: 2.011-7.975, Conclusion and recommendation: This study revealed that the magnitude of zero-dose children is 17%, and demonstrated that zero-dose vaccination in Southwest Ethiopia is best understood through a multi-level ecological lens. While quantitative analysis identified antenatal care attendance, maternal knowledge/information, and gravidity as significant predictors, qualitative findings revealed how individual knowledge gaps, interpersonal influences, institutional service limitations, and broader structural barriers in underserved agrarian and pastoralist settings intersect to shape immunization behavior.