Factors Associated with Zero-Dose Status Among Children Aged 12–23 Months in the Mobayi-Mbongo Health Zone, North Ubangi Province, Democratic Republic of the Congo, from January to December 2024: A Cross-Sectional Study

Background Zero-dose children—those who have not received any dose of the first dose of pentavalent vaccine (Penta1), remain a major public health concern in the Democratic Republic of Congo (DRC). Understanding the determinants of zero-dose status is essential for improving immunization coverage and reducing vaccine-preventable diseases. Methods An analytical cross-sectional study was conducted from January to December 2024. A three-stage cluster sampling technique was used to select 203 children aged 12–23 months across six health areas. Data were collected through structured electronic questionnaires (KoboCollect), direct observation, and vaccination card review. Statistical analyses were performed using SPSS version 25, with bivariate and multivariate logistic regression to identify associated factors. Results The prevalence of zero-dose children was 28.6% when combining vaccination card data and maternal declarations. Multivariate analysis revealed that Central African nationality of mothers/caregivers (AOR = 5.9; 95% CI : 3.01–11.58), lack of knowledge of vaccine-preventable diseases (AOR = 16.09; 95% CI : 3.35–77.29), young maternal age (< 20 years) (AOR = 2.06; 95% CI : 1.10–3.86), and distance to vaccination sites > 5 km (AOR = 4.22; 95% CI : 2.21–8.05) were significantly associated with zero-dose status. Conclusion Zero-dose prevalence remains high in the Mobayi-Mbongo Health Zone, driven by sociodemographic, knowledge-related, and geographic barriers. Targeted interventions focusing on refugee populations, health education, improved geographic accessibility, and support for young mothers are urgently needed to reduce inequities in immunization coverage.