Factors associated with non-completion of vaccinations in children under five (05) years of age in the health district of Kousseri, Far north, Cameroon

Incomplete immunization among children under five years of age remains a major public health concern, particularly in low-resource settings. This study aimed to identify socio-demographic, socio-cultural, and organizational factors associated with vaccine non-completion in the Kousseri health district. We conducted a cross-sectional descriptive study with prospective data collection. Mothers of children aged 11–23 months were surveyed using WHO vaccine coverage standards. A total of 41 clusters of 7 mothers each were selected, yielding a sample size of 287. Odds ratios (OR) and confidence intervals (CI) were calculated to assess associations between risk factors and immunization completion. Children living in health areas without community relays were more likely to have incomplete immunization (OR = 4.6; 95% CI: 0.6–36.1). Mothers not enrolled in mutual health insurance, lacking knowledge of Expanded Program on Immunization (EPI) diseases, or not trusting health care staff had higher risks of incomplete vaccination (OR = 5.7, 9.5, and 3.9, respectively). Organizational gaps also contributed: staff without motivation or retraining were associated with increased risk (OR = 6.1; 95% CI: 0.7–47.3 and OR = 13.5; 95% CI: 1.2–145.7). Conversely, the presence of immunization focal points and vaccination registries were protective factors (OR = 0.4; 95% CI: 0.08–1.9 and OR = 0.01; 95% CI: 0.001–0.27). In conclusion, socio-cultural and organizational barriers significantly contribute to incomplete immunization. Strengthening community outreach, motivating and retraining staff, improving registry management, and raising awareness among mothers, spouses, and young girls are essential strategies to improve vaccination coverage among children under five.