Vaccination Coverage and Timelines Among Children 0–6 Months in Kinshasa, the Democratic Republic of Congo: A Prospective Cohort Study

Objectives The Democratic Republic of Congo (DR Congo) is one of the ten countries, which accounts for 60% of unvaccinated children worldwide. The aim of this study was to assess predictors of incomplete and untimely immunization among a cohort of infants recruited at birth and followed up through 24 weeks in Kinshasa. Methods Complete immunization for each vaccine was defined as receiving all the recommended doses. Untimely immunization was defined as receiving the given dose before (early) or after (delayed) the recommended time window. Infants not immunized by the end of the follow-up time were considered missing. Multivariate hierarchical model and generalized logistic model were used to assess the independent contribution of each socio-economic and demographic factors considered to complete immunization and timeliness, respectively. Results Overall, of 975 infants from six selected clinics included in the analysis 84.7% were fully immunized the three doses of DTP or four doses of Polio by 24 weeks of age. Independently of the vaccine considered, the strongest predictor of incomplete and untimely immunization was the clinic in which the infant was enrolled. This association was strengthened after adjustment for socio-economic and demographic characteristics. Education and the socio-economic status also were predictive of completion and timeliness of immunization in our cohort. Discussion In conclusion, the strongest predictor for incomplete and untimely immunization among infants in Kinshasa was the clinics in which they were enrolled. The association was likely due to the user fee for well-baby clinic visits and its varying structure by clinic.