ASA Monitor February 2024, Vol. 88, 16.
Vaccine approval for chikungunya virus
The U.S. Food and Drug Administration (FDA) has granted approval to Ixchiq, marking the first vaccine for chikungunya virus. Designed for individuals aged 18 and older at an elevated risk of chikungunya virus exposure, the vaccine addresses an emerging global health threat with over 5 million reported cases in the past 15 years. Chikungunya, primarily transmitted by infected mosquitoes, poses a significant risk in tropical and subtropical regions globally. The safety of Ixchiq, administered as a single-dose injection into the muscle, was assessed in two clinical studies involving over 3,500 participants, with common side effects including headache, fatigue, and joint pain. Ixchiq’s approval is based on immune response data, with almost all vaccine recipients achieving the protective antibody level. The Accelerated Approval pathway was utilized, allowing approval based on evidence of effectiveness predicting clinical benefit. Confirmatory clinical studies are required as a condition for approval. Severe chikungunya-like adverse reactions occurred in 1.6% of Ixchiq recipients. Due to the serious risk of severe chikungunya-like adverse reactions, the FDA is mandating a postmarketing study. Additionally, the vaccine’s potential transmission from pregnant individuals to newborns is a consideration, and health care providers are advised to assess individual risk factors.