Abstract
BACKGROUND: In Somalia, a fragile state characterized by protracted conflict and fragmented health governance, childhood immunization remains a critical challenge. The third dose of the Diphtheria-Tetanus-Pertussis (DTP3) vaccine serves as a key indicator of health system performance and retention. This study aimed to identify structural and individual-level determinants of DTP3 coverage to understand the inequities in this humanitarian setting. METHODS: A cross-sectional analysis was conducted using data from the 2020 Somali Health and Demographic Survey (SHDS). A total sample of 1,268 children was analyzed. Multilevel mixed-effects logistic regression models were fitted to account for the hierarchical structure of the data (children nested within communities). Fixed effects were reported as adjusted odds ratios (aOR) with 95% confidence intervals (CI). RESULTS: The overall prevalence of DTP3 vaccination coverage was 39.51% [95% CI: 36.85-42.23]. At the individual level, higher maternal education (Secondary vs. no education: aOR = 1.83; 95% CI: 1.07-3.12), wealth status (Rich vs. poor: aOR = 2.41; 95% CI: 1.53-3.79), and antenatal care (ANC) attendance (3-4 visits vs. zero visits: aOR = 2.19; 95% CI: 1.43-3.36) were significantly associated with higher odds of vaccination. Older children had higher odds of vaccination compared to infants, suggesting delayed rather than timely uptake. At the community level, children in rural (aOR = 0.40; 95% CI: 0.28-0.57) and urban (aOR = 0.64; 95% CI: 0.45-0.91) areas had lower odds of vaccination compared to those in nomadic communities. Significant regional disparities were also observed. CONCLUSIONS: DTP3 coverage in Somalia is critically below the WHO 90% target. Vaccination status is shaped by a complex interplay of socioeconomic status, maternal healthcare utilization, and geographic location. Policy interventions must urgently address the 'urban penalty' identified in this study, where settled urban-poor populations now face lower odds of vaccination than nomadic groups targeted by mobile outreach.