Gender and equity barriers associated with complete childhood vaccination in six health districts of Cameroon: a mixed-methods study

Background Despite the progress Cameroon's Expanded Programme on Immunization (EPI) has made, persistent inequalities in vaccination coverage reveal structural gender and equity barriers. This study aimed to identify and analyze these barriers in six priority health districts, to generate actionable evidence for strengthening equity in routine immunization services. Methods A mixed-methods study was implemented in March 2026 in six health districts representative of Cameroon's geographic, linguistic and security diversity: Belel (Adamaoua region), Mokolo (Far North), Touboro (North), Kumbo West and Wum (North-West), and Tiko (South-West). The quantitative component covered 1,451 households with at least one child aged 0–23 months, selected through multi-stage cluster sampling. A composite female-autonomy index and household wealth tertiles were constructed. Logistic regression models were fitted to identify determinants of complete vaccination, overall and by geographic zone (northern/southern districts). The qualitative component included 24 key-informant interviews with community and health-system actors and 12 focus group discussions with compliant and non-compliant parents, analyzed thematically using NVivo. Ethical approval was obtained from Cameroon's National Ethics Committee for Human Health Research (N°2026/04/1907/CE/CNERSH/SP/SPA). Results Overall complete age-appropriate vaccination coverage was 73.4%, ranging from 58.8% in Belel to 96.9% in Kumbo West. Mothers accompanied children to vaccination in 95.5% of cases, yet paternal permission was required in 26.8% of households (100% in Belel), and fathers alone controlled household finances for transport and care in 53.2% of cases. Inconvenient scheduling of vaccination sessions was the strongest supply-side predictor of incomplete vaccination (adjusted odds ratio [aOR] = 0.22; 95%CI 0.08–0.60; p = 0.003). Household wealth was the strongest overall predictor of complete vaccination (third versus first tertile: aOR = 2.22; 95%CI 1.32–3.72; p = 0.002). In southern districts, travel time exceeding 60 minutes reduced the odds of complete vaccination three-fold (aOR = 0.29; 95%CI 0.09–0.91; p = 0.033). Vaccine stock-outs were significantly associated with incomplete vaccination in northern districts (aOR = 0.42; 95%CI 0.18–0.98; p = 0.045). Place of birth was a robust predictor across all models (aOR = 2.36; 95%CI 1.68–3.30; p < 0.001). Positive-masculinity profiles (fathers financing transport, caring for other children, accompanying their spouse) were identified in every region as a mobilizable lever. Conclusions Rather than operating as an isolated obstacle, gender dynamics appear as a critical booster factor, amplifying and exacerbating existing systemic constraints. In fragile districts surveyed, incomplete vaccination and programmatic underperformance are primarily driven by hard structural, logistical, and institutional barriers. Sustainably improving coverage in the most disadvantaged districts requires the simultaneous engagement of men, strengthening of women's autonomy, support for community health workers, and correction of health-system deficiencies.