The use of Valneva’s chikungunya vaccine, known under the brand name Ixchiq, has been paused in elderly individuals after reports of serious adverse events (AEs)
The US Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC) recommended the suspension of the vaccine in individuals aged 60 years and over on 9 May while they investigate the safety concerns.
Go deeper with GlobalData
The decision follows a similar one by the European Medicines Agency (EMA) on 7 May, which also paused the vaccine’s use in adults aged 65 years and older and those with weakened immune systems as part of an ongoing review.
Shares in the French vaccine maker have sequentially dropped over the past few days in the wake of the news. Share price was down 6.8% at market open on 12 May compared to 6 May, a day before the EMA safety notice.
The FDA stated there have been 17 serious AEs in people aged between 62 and 89 years as of 7 May, two of which have resulted in death. Reported cases have been in patients with underlying chronic medical conditions, with the agency saying the adverse events “may not be causally related to vaccination”.
The two fatal cases occurred in the French overseas department of La Réunion. Valneva sent 40,000 doses to the territory in March 2025 as part of a national vaccination drive to prioritise older adults with co-morbidities. According to the EMA, one of the fatal cases was an 84-year-old man who developed encephalitis while the other was a 77-year-old man with Parkinson’s disease whose swallowing difficulties may have caused aspiration pneumonia.
US Tariffs are shifting - will you react or anticipate?
Don’t let policy changes catch you off guard. Stay proactive with real-time data and expert analysis.
By GlobalData“FDA will conduct an updated benefit-risk assessment for the use of Ixchiq in individuals 60 years of age and older. In addition, FDA and CDC will continue the evaluation of post-marketing safety reports for Ixchiq,” the FDA said in a statement.
Licensed to prevent the disease caused by the chikungunya virus in adults, Ixchiq was approved by the FDA and EMA in November 2023 and June 2024, respectively.
Chikungunya, caused by its namesake virus, is a mosquito-borne disease mainly found in tropical regions. Although cases are not prevalent in North America or Europe, there is a risk of disease transmission to travellers visiting outbreak-affected countries in Africa and South America, along with islands in the Indian and Pacific Oceans.
Symptoms include fever and severe joint pain, which are similar to Dengue and Zika infections, making it difficult to diagnose.
Ixchiq is a live, attenuated version of the virus administered as a single dose by injection. The vaccine may cause symptoms like those experienced by people who have chikungunya disease.
The safety of Ixchiq was evaluated in two clinical studies conducted in North America in which approximately 3,500 participants aged 18 years and older received a dose of the vaccine, while roughly 1,000 participants received a placebo. Alongside AEs such as headache, fatigue, and muscle pain, severe events occurred in 1.6% of Ixchiq recipients and none in the placebo group. Two recipients in the trials who experienced severe chikungunya-like adverse reactions were hospitalised.
In a 12 May statement, Valneva said that it is “committed to upholding the highest safety standards” and is engaging with health authorities. The French company said it continues to see a positive risk-benefit in the vast majority of people with potential disease exposure.
Valneva’s chief medical officer Juan Carlos Jaramillo said: “We reiterate our support for the precautionary measures that have been taken as well as our commitment to continue monitoring all reported serious AEs […] we will continue engaging proactively with the global regulatory authorities while these important investigations continue over the coming months.”
Around 43,400 doses of Ixchiq have been used globally. For a while, it was the only licensed vaccine for chikungunya virus prevention until Bavarian Nordic’s Vimkunya entered the market in February 2025. Both Vimkunya and Ixchiq are also approved in adolescents in Europe, the latter’s license coming via a label expansion in April 2025. In the US, only Vimkunya is currently approved for both age groups.
Sales for Ixchiq have been underwhelming since the commercial rollout, generating €3.7m globally last year.
