Determinants of Under-Immunization Among Children Between 0 and 59 Months in Buea Municipality, South Western Cameroon: Implications for National Immunization Campaign

Introduction: Under-immunization remains a major global public health concern. The World Health Organization (WHO) reports that approximately 20 million children globally are not fully vaccinated, with more than half of these children residing in Africa. African countries including Cameroon face unique challenges in achieving high vaccination coverage. This study aimed to determine the prevalence and determinants of under-immunization among children aged 0–59 months in Buea, Cameroon to contribute to effective national immunization policy. Methods: This cross-sectional study used the World Health Organization Behavioural and Social Determinants of vaccination tool to collect data from 438 caregivers of children aged 0–59 months in the city of Buea. Data were collected on socio-demographics, immunization factors, and health system variables for the study cohort. Results: It was found that 25.11% of children in urban Buea were under-immunized. Children in Buea Town were three times more likely to be under-immunized than those in Molyko (AOR = 3.0, 95% CI: 1.3–7.3, p = 0.013). Children of separated caregivers were 0.2 times less likely to be under-immunized than those of widowed caregivers (AOR = 0.2, 95% CI: 0.1–0.9, p = 0.036). Children whose caregivers did not receive unsolicited advice were 2.1 times more likely to be under-immunized (AOR = 2.1, 95% CI: 1.2–3.4, p = 0.006). Children living less than 1 mile from health facilities were 2.9 times more likely to be under-immunized than those living more than 10 miles away (AOR = 2.9, 95% CI: 1.1–7.5, p = 0.030). Children of caregivers employed in the private sector were 4.3 times more likely to be under-immunized compared to those of unemployed caregivers (AOR = 4.3, 95% CI: 1.1–16.2, p = 0.031). Children in non-owned/non-rented houses were 0.3 times less likely to be under-immunized compared to those in rented houses (AOR = 0.3, 95% CI: 0.1–0.9, p = 0.030). Children whose caregivers did not discuss vaccination concerns with healthcare workers were 0.6 times less likely to have under-immunized children (COR = 0.6, 95% CI: 0.3–0.9, p = 0.020). Conclusions: It was concluded that under-immunization is a significant public health problem in the city of Buea. Interventions that target the quality of services, community engagement, and the unique challenges faced by different caregiver groups, are needed.