The US Food and Drug Administration (FDA) has lifted a pause in the use of Valneva’s chikungunya vaccine Ixchiq in older adults after a benefit-risk reevaluation, though the move comes with an adjustment in the individuals allowed to receive the jab.
Shares in Paris-listed Valneva opened 11% higher on 8 August at €3.63. The vaccine specialist, which has a market cap of €636m, relayed the news on 7 August.
In May 2025, the FDA and the US Centers for Disease Control and Prevention (CDC) jointly recommended a pause in the vaccine’s use in those aged 60 and over after post-marketing reports of serious adverse events.
This included two deaths on the island of La Réunion during a mass vaccination campaign following a significant outbreak of chikungunya. According to the European Medicines Agency (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.
As part of its investigation into the safety of the vaccine, the FDA completed an updated benefit-risk assessment of Ixchiq in individuals aged 18 years and older.
Along with removing the pause, the FDA has tweaked the prescribing information for the vaccine. Ixchiq is now indicated for the prevention of disease caused by the chikungunya virus in individuals 18 years of age and older who are at high risk of exposure to the virus. The vaccine was originally indicated for those who were at increased risk.
The two decisions by the FDA follow similar ones made by the EMA in July – the European regulator saying the vaccine should be used when there is a “significant risk” of infection.
The FDA also updated the limitations of use section for the vaccine. The agency states that most US travellers do not need to take Ixchiq due to the low risk of chikungunya exposure. The existing contraindication in individuals with weakened immune systems also remains.
Despite the narrowing of the vaccine's licence, the clearance by both the FDA and EMA to continue use of Ixchiq will be welcome news to Valneva.
The French vaccine specialist only has three vaccines in its commercial portfolio, with Ixchiq being the most recently approved. In 2024, it generated €3.7m, though sales of the vaccine are likely to increase based on the new wave of chikungunya outbreaks occurring globally.
The European Centre for Disease Prevention and Control (ECDC) states that, as of July 2025, there are around 240,000 cases across 16 countries or territories. The CDC has issued a considerable number of chikungunya-related travel alerts for outbreaks. This includes one in China’s Guangdong province that has received media attention due to the government’s strict response to containing cases.
For a while, Ixchiq 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 licence coming via a label expansion in April 2025. In the US, only Vimkunya is currently approved for both age groups.
