Acceptance of chikungunya vaccination: a rapid survey in Reunion island during an epidemic

Abstract

During the 2025 chikungunya outbreak in Réunion Island, two vaccines-IXCHIQ (live-attenuated) and VIMKUNYA (virus-like particle)-received European Union authorization; a local campaign began in April 2025 and was temporarily adjusted for older adults after safety concerns. We assessed vaccine acceptability at the outbreak onset among residents, focusing on people with comorbidities. In January 2025, a cross-sectional web survey yielded 918 complete responses (mean age 44.5 years; 13.1 % prior chikungunya; 53.4 % healthcare workers). Acceptability was highest in the hypothetical full-reimbursement scenario (60.5 %) and was lower among women and those with prior chikungunya; healthcare workers were more likely to accept vaccination. In the hypothetical clinical-trial and self-financed scenarios, acceptability declined to 35.5 % and 20.1 %, respectively, with the same pattern of predictors. Comorbidities showed no significant association. Financing and implementation context, together with gender differences, were key drivers of uptake at the beginning of 2025 outbreak.

Keywords: Chikungunya; Comorbidities; Healthcare workers; La Réunion Island; Public health; Vaccine acceptability.