Optimizing childhood vaccination coverage in Lubumbashi: Expert perspectives on the SCAVA / VACCIN+CONNECT- OS initiative

The Expanded Programme on Immunization (EPI) is a public health intervention aimed at reducing child morbidity and mortality caused by vaccine-preventable infectious diseases, particularly in low-income countries. The Democratic Republic of Congo (DRC) is a country that introduced the national EPI program in 1978. Different ways exist to implement the EPI. The DRC opted for an initiative taken by the family. The coverage is however low, because the country did not conduct a research that identifies factors that constrain optimal vaccine implementation when the decision is at the household level. To get support for a project that investigates that knowledge, a survey was conducted among immunization experts to assess whether exploring the determinants of vaccination coverage in the city of Lubumbashi is worthwhile. Experts were purposively selected through a multidisciplinary approach, targeting individuals with substantial national and international experience in vaccine program implementation, both globally, locally in Africa, and in the DRC. An open-ended questionnaire was developed to explore expert perspectives on optimal vaccine delivery strategies that was conceived in the locally developed SCAVA / VACCIN+CONNECT- OS project (Adaptive Strategy for the Control of Vaccination Activities). Responses were analyzed using mixed quantitative and qualitative methods to identify expert consensus on the need for a local determinants study to enhance vaccine delivery. A total of 167 experts were contacted, and 111 responded (66%). Respondents represented a diverse sample in terms of gender (64% male), age (>50 y: 43%), experience (<10 y: 43%), and professional scope (local/global: 75%). Eighty percent (90/111) supported the initiation of the SCAVA / VACCIN+CONNECT- OS study, followed by the development of an actionable plan to address the identified barriers. They specified multiple reasons and causes of vaccine hesitancy at the household level. Twenty percent (21/111) held a different opinion, citing the immediate need for financial, logistical, and material resources to strengthen vaccination services. The survey demonstrates strong expert support for launching a determinant-focused study like SCAVA / VACCIN+CONNECT- OS as a prerequisite to successful and sustainable vaccination implementation in the DRC. The majority advocated for socio-anthropological and communication-centered public health models, addressing local economic, cultural, and behavioral factors, as an essential foundation for improving childhood immunization coverage.