Chikungunya Vaccine Under Safety Review by EMA
The European regulatory body’s safety committee has started its review of the vaccine after receiving reports of serious adverse events in elderly patients.
The European Medicines Agency (EMA) has announced that its Pharmacovigilance Risk Assessment Committee (PRAC) has started a review of the live attenuated chikungunya vaccine, Ixchiq, after receiving reports of elderly patients experiencing serious adverse events. The precautionary safety review was announced in a May 7, 2025 press release by EMA (1).
Prior to the safety review, PRAC had received 17 reports of serious adverse events, including two cases that have resulted in death, in people between 62 and 89 years of age who had received the vaccine. Although many of these people also had other illnesses, the exact cause of the serious adverse events and the potential relationship with the vaccine need to be determined.
The vaccine’s developer, Valneva, originally received authorization from the European Commission (E.C.) for Ixchiq to be used as a single-dose vaccine for chikungunya on June 28, 2024 (2). With this authorization, the vaccine became the first one available for the prevention of chikungunya, which is a disease transmitted by mosquitoes (3).
“We are deeply concerned by the reports of adverse events experienced by elderly individuals. Valneva remains committed to upholding the highest safety standards and respects the precautionary measures taken by authorities as investigations continue,” said Juan Carlos Jaramillo, M.D., Chief Medical Officer of Valneva, in a company press release (4). “The Company will continue to monitor all reported serious adverse events and fully cooperate with health authorities while also actively exploring a potential update to the product’s indication.”
While PRAC performs its review of all available data, a temporary safety measure has been put in place for the vaccine, specifying that it must not be used in people aged 65 years and above. Additionally, PRAC has also issued a reminder to healthcare professionals about not using the live attenuated vaccine in people who have a weakened immune system as a result of disease or medical treatment.
The vaccine is approved for use in the U.S., Canada, and U.K. as well as the European Union. Updated recommendations to the use of the vaccine, which caution about its use in patients aged 65 years and older, especially those with comorbidities, have been made in the U.S. and France (5,6). At the time of writing, the vaccine has already been administered in over 40,000 patients worldwide (1).
References
EMA. EMA Starts Review of Ixchiq (Live Attenuated Chikungunya Vaccine). News Release, May 7, 2025.
Valneva. Valneva Receives Marketing Authorization in Europe for the World’s First Chikungunya Vaccine, IXCHIQ. Press Release, July 1, 2024.
E.C. Commission Authorizes Chikungunya Vaccine and Funds New Mosquito Eradication Programme. Press Release, June 28, 2024.
Valneva. Valneva Provides Update Following European Medicines Agency Announcement on Use of IXCHIQ in Elderly. Press Release, May 7, 2025.
Valneva. Valneva Provides Update on ACIP Recommendation for its Chikungunya Vaccine IXCHIQ Among U.S. Travelers. Press Release, April 18, 2025.
Valneva. Valneva Provides Update on Recommendation for Use of Its Chikungunya Vaccine by French Authorities. Press Release, April 26, 2025.