Clinical Research Directory

Inclusion criteria: * The participant or guardian understands the procedures and requirements, and is willing and able to provide informed consent for full participation in the study; * Individuals of both sexes aged 12 to 59 years. Exclusion Criteria: * Participants under 12 years of age or 60 years of age or older; * Those with any contraindication identified in Ministry of Health Technical Note No. 9/2026-CGFAM/DPNI/SVSA/MS (https://www.gov.br/saude/pt-br/centrais-de-conteudo/publicacoes/notas-tecnicas/2026/nota-tecnica-no-9-2026-cgfam-dpni-svsa-ms.pdf - Technical Note: Guidelines for monitoring the safety of the Chikungunya vaccine used during the pilot vaccination strategy in Brazil - 2026); * Participants unavailable to attend the planned study visits; * Participants who do not agree to sign the Informed Consent Form (ICF); * Positive β-hCG test on the day of vaccination, for women of reproductive potential; * Participants who are pregnant or planning to become pregnant within the 3 months following the vaccine dose; * Participants who are breastfeeding; * Participants with a known or suspected immune system defect that could influence the immune response to the vaccine, such as congenital or acquired immunodeficiency-including HIV infection, post-organ transplant status, or immunosuppressive therapy within 4 weeks prior to Visit 1. Immunosuppressive therapy is defined as the chronic administration of prednisone (more than 14 days) or an equivalent at a dosage of ≥2 mg/kg/day during the 4 weeks prior to study entry. Note: radiotherapy or cytotoxic immunosuppressive drugs/monoclonal antibodies within the previous 3 years; topical and inhaled steroids are permitted. * Any clinical instability identified by the attending physician that could place the participant at risk.