From vaccine availability to effective deployment: Closing the arboviral vaccine access gap

Mosquito-borne viral diseases are expanding globally, yet programmatic access to dengue and chikungunya vaccines remains limited or uneven in many high-risk settings. Using country-level classifications of regulatory approval and national immunization program inclusion, we identify substantial gaps between vaccine availability and areas at greatest epidemiological risk. The central challenge extends beyond vaccine feasibility to a multilayered vaccine-access gap spanning initial availability, sustained deployment and alignment with transmission risk. Current vaccine strategies remain reactive and insufficiently adapted to epidemiological patterns and health-system demands. Closing this gap will require preparedness-oriented frameworks that support timely introduction, durable coverage, and risk-adaptive deployment.