Vaccination Dropout Rates Among Children Aged 12-23 Months in the Urban-Rural Health District of Mont Ngafula II, Democratic Republic of the Congo: A Cross-sectional Study

Abstract Background: Globally, 1.8 million children failed to receive the 3-dose diphtheria, tetanus and pertussis (DTP) series every year in the Democratic Republic of the Congo (DRC). Currently, an emergency plan targeting 9 provinces, including the capital of Kinshasa, is launched to reinforce routine immunization. The Mont Ngafula II health district (HD) was the only one to report high vaccination dropout rates over almost five consecutive years. This study aimed to assess issues within the local dynamic system of vaccination services and identify associated risk factors among children aged 12-23 months. Methods: A cross-sectional household survey was conducted among 418 children in June-July 2019 using a two-stage sampling design. Socio-demographic and perception data were collected through a structured interviewer-administered questionnaire. The distribution of 2017-2018 immunization coverage and dropout rate was extracted from local authority of HD and mapped. Chi-square test and multivariate logistic regression were used to identify predictors of high vaccination dropout. Statistical significance was defined as p < 0.05. Results: Of 14 health areas included in the Mont Ngafula II HD, four reported high vaccine coverage, only one recorded low vaccine coverage and three registered both low vaccine coverage and high dropout rate. Multivariate logistic regression showed the predictors of immunization dropout as follows: no possession of immunization card (aOR = 2.49; 95% CI = 1.25-4.93; p = 0.010), living in rural areas (aOR = 1.53; 95% CI = 1.02-2.32; p = 0.042), unavailability of seating places (aOR = 7.10; 95% CI = 1.39-36.27; p = 0.019), no respect of the order of arrival (aOR = 3.88; 95% CI = 1.48-10.16; p = 0.006) during vaccination in health facilities, and the lack of a reminder system on days before the scheduled vaccination (aOR = 2.17; 95% CI = 1.43-3.32; p < 0.001). Conclusion: The poor utilization of immunization services seemed as the main health concern followed by the poor access. Residing in rural areas, no immunization card possession, absence of seating places, no respect of the order of arrival, and the lack of a reminder system were the predictors of vaccination dropout rates. These results advocate for prioritizing targeted interventions and programs that will strengthen interpersonal communication between vaccination service providers and users during vaccination in health facilities as well as implement and extend a reminder system using SMS reminders on days before the scheduled vaccination.