Surveillance for adverse events following use of live attenuated chikungunya vaccine, United States, 2024, and the associated public health response in 2024 and 2025
Susan L. Hills, Rebekah Sutter, Elaine R. Miller, Edwin J. Asturias, Lin H. Chen, Beth P. Bell, Michael M. McNeil, Jeffrey Rakickas, Melinda Wharton, Sarah Meyer, J. Erin Staples
Abstract
A live attenuated chikungunya vaccine (IXCHIQ) received licensure in the United States (US) for ≥ 18-year-olds in November 2023. Post-licensure safety surveillance identified 28 adverse events in 2024 among US persons, including six neurological or cardiac serious adverse events (SAEs) in males ≥ 65 years. In early 2025, providers were alerted, a precaution for older persons was issued and vaccine guidance was updated. In May, following 11 additional SAEs reported outside the US, use in older persons was temporarily paused until 6 August 2025.
Topics & Concepts
LicensureMedicineAdverse effectChikungunyaPublic healthEnvironmental healthPediatricsMedical emergencyVirologyOutbreakInternal medicineNursingMosquito-borne diseases and controlVirology and Viral DiseasesVaccine Coverage and Hesitancy