Determinants of covid-19 vaccine uptake and post-vaccination symptoms among at-risk populations in Mbujimayi, DRC

Background: COVID-19 vaccination remains a key strategy for reducing SARS-CoV-2 transmission and protecting high-risk populations. In resource-limited settings such as the Democratic Republic of Congo (DRC), improving vaccination coverage and addressing vaccine safety concerns are crucial for the success of public health programs.

Methods: A cross-sectional survey was conducted between October and December 2023 among 560 at-risk individuals in the Bonzola Health Zone, Mbujimayi. Data were collected using questionnaires administered via smartphones. Logistic regression (SPSS v25) was used to identify predictors of vaccination coverage and post-vaccination symptoms.

Results: Among the 560 participants (173 women, 387 men; median age: 30 ± 16.9 years), 77% had received at least one dose of a COVID-19 vaccine. The most commonly administered vaccine was Johnson & Johnson (62.7%), followed by AstraZeneca, Moderna, Sinovac, and unspecified types. Post-vaccination symptoms were reported by 57.7% of participants, primarily local pain, erythema, myalgia, and chills. The main factors associated with vaccination were: advanced age (OR = 1.025; 95% CI: 1.020–1.030; p = 0.001), male sex (OR = 2.392; CI: 1.725–3.317; p = 0.001), presence of comorbidities (OR = 3.872; CI: 3.019–4.966; p = 0.001), being a healthcare professional (OR = 4.453; CI: 3.467–5.721; p = 0.001), number of doses received (OR = 1.61; CI: 1.2–2.1; p = 0.001), motivation to get vaccinated (OR = 21.4; CI: 13.7–33.5; p = 0.001), and the vaccine type (OR = 3.0; CI: 2.38–3.18; p = 0.001). Post-vaccination symptoms were associated with occupation (OR = 0.89; CI: 0.82–0.96; p = 0.001), number of doses received (OR = 5.11; CI: 2.9–9.1; p = 0.001) and vaccine type (OR = 4.5; CI: 1.8–10.8; p = 0.001).

Conclusion: In a context marked by limited access, vaccine hesitancy, and misinformation, understanding demographic and behavioral predictors is essential. These findings provide evidence to adapt vaccination strategies, build trust, and support informed communication with vulnerable populations.

To be updated shortly..