Factors associated with non-vaccination of children aged 12 to 23 months in Lomami Province: secondary analysis of data from the 2023 vaccination coverage survey

Background Despite ongoing immunisation efforts, vaccination coverage among children aged 12–23 months remained suboptimal in 2024, with 9.3% of children unvaccinated and 40.9% only partially vaccinated. These gaps are particularly marked among internally displaced populations and refugees. This study assessed the determinants of childhood non-vaccination in Lomami Province, Democratic Republic of Congo, using data from the 2023 vaccination coverage survey. Methods This study involved a secondary analysis of data from the vaccination coverage survey conducted by the School of Public Health, University of Kinshasa. The analytical sample comprised 1,580 children aged 12–23 months drawn from 2,630 households across health zones in Lomami Province. Descriptive statistics, chi-square tests, and multivariable logistic regression analyses were used to identify factors associated with non-vaccination. Results Approximately one-third of respondents were aged 20–24 years, and 96% were mothers or primary caregivers. Nearly 10% of children had received no vaccines. Health-system barriers were prominent: 47% of caregivers reported vaccine stock-outs and 30% cited long waiting times at health facilities. In addition, about 40% of respondents expressed reluctance toward vaccination. Non-vaccination was significantly associated with low socioeconomic status, low maternal educational attainment, and marital instability, with children of divorced mothers being nearly four times more likely to be unvaccinated. Children of civil servants were also less likely to be fully vaccinated. Conclusions Childhood immunisation coverage in Lomami Province remains inadequate and is influenced by both demand- and supply-side factors. Strengthening vaccine supply chains, improving service delivery, and enhancing community awareness and engagement are critical to achieving more equitable and complete vaccination coverage.