Despite efforts to increase childhood vaccination coverage in the Democratic Republic of the Congo (DRC), approximately 20% of infants have not started their routine immunization schedule (zero-dose). The present study aims to evaluate the relative influence of geospatial access to health facilities and caregiver perceptions of vaccines on the vaccination status of children in rural DRC. Pooled data from two consecutive nationwide immunization surveys conducted in 2022 and 2023 were used. Geographic accessibility was assessed based on travel time from households to their nearest health facility using the AccessMod 5 model. Caregiver attitudes to vaccination were assessed using the survey question How good do you think vaccines are for your child? We used logistic regression to assess the relationship between geographic accessibility, caregiver attitudes toward vaccination, and their childs vaccination status. Geographic accessibility to health facilities was high in rural DRC, with 88% of the population living within an hours walk to a health facility. Responding that vaccines are Bad, Very Bad, or Dont Know relative to Very Good for children was associated with a many-fold increased odds of a zero-dose status (ORs 69.3 [95%CI: 63.4-75.8]) compared to the odds for those living 60+ min from a health facility, relative to <5 min (1.3 [95%CI: 1.1-1.4]). Similar proportions of the population fell into these two at-risk categories. We did not find evidence of an interaction between caregiver attitude toward vaccination and travel time to care. While geographic access to health facilities is crucial, caregiver demand appears to be a more important driver in improving vaccination rates in rural DRC.

BACKGROUND: Low immunization coverage rates in the Democratic Republic of Congo (DRC) have been reflective of challenges with vaccine access, support and delivery in the country. Motivated by measles and vaccine-derived polio virus (VDPV) outbreaks in 2016-17 and low vaccination rates, the provinces of Haut Lomami and Tanganyika were identified as pilot locations for an innovative approach focused on establishing a consortium of partners supporting local government. This approach was formalized through Memorandums of Understanding (MoUs) between the Bill and Melinda Gates Foundation and Provincial governments in 2018. A third province, Lualaba, established an MoU in 2021. MOU IMPLEMENTATION: These MoUs were 5-year partnerships designed to aid provinces in meeting four key objectives: 80 % immunization coverage, management/elimination of polio/cVDPV outbreaks, improvement of vaccine accessibility, and transfer of immunization service management to provincial leadership. OUTCOMES: During the MoU period, Haut-Lomami saw an increase in full immunization coverage, from 35.7 % (MICS 2018) to 88.9 % (VCS 2021-22), the highest in country. A sharp drop in percentage of zero-dose children was observed in the 3 provinces, confirming improved access to immunization services. Tanganyika saw initial improvement in full immunization coverage, followed by a drop in the VCS 2021-22 due to COVID-19 and healthcare worker strikes. Coverage improved in Tanganyika in the 2023 VCS. The 3 provinces increased their financial contributions to routine immunization and are now the top contributing provinces. While no cVDPV cases were recorded in 2020 and 2021, cVDPV1 and cVDPV2 outbreaks are afflicting the 3 provinces since 2022. CONCLUSIONS: Ultimately, the provincial MoUs were successful in bolstering provincial autonomy and capacity building with the biggest success being a drop in zero-dose children. While not all objectives have been met, the MoU approach served as an innovative program for key aspects of strengthening routine immunization in the DRC.

Background

The immunization system in the Democratic Republic of the Congo faces many challenges, including persistent large-scale outbreaks of polio, measles, and yellow fever; a large number of unvaccinated children for all antigens; minimal and delayed funding; and poor use of immunization data at all levels. In response, the Expanded Programme on Immunization within the Ministry of Health (MOH) collaborated with global partners to develop a revitalization strategy for the routine immunization (RI) system called the Mashako Plan.

Mashako plan design and development

The Mashako Plan aimed to increase full immunization coverage in children aged 12-23 months by 15 percentage points overall in 9 of 26 provinces within 18 months of implementation. In 2018, we conducted a diagnostic review and identified gaps in coordination, service delivery, vaccine availability, real-time monitoring, and evaluation as key areas for intervention to improve the RI system. Five interventions were then implemented in the 9 identified provinces.

Discussion

According to the 2020 vaccine coverage survey, full immunization coverage increased to 56.4%, and Penta3/DTP3 increased to 71.1% across the Mashako Plan provinces; the initial objective of the plan was reached and additional improvements in key service delivery indicators had been achieved. Increases in immunization sessions held per month, national stock of pentavalent vaccine, and supervision visits conducted demonstrate that simple, measurable changes at all levels can quickly improve immunization systems. Despite short-term improvements in all indicators tracked, challenges remain in vaccine availability, regular funding of immunization activities, systematic provision of immunization services, and ensuring long-term sustainability.

Conclusions

Strong commitment of MOH staff combined with partner involvement enabled the improvement of the entire system. A simple set of interventions and indicators focused the energy of managers on discrete actions to improve outcomes. Further exploration of the results is necessary to determine the long-term impact and generate all-level engagement for sustainable success in all provinces.