The FDA has removed a pause in the use of Valneva’s chikungunya vaccine in older adults while tweaking the shot’s label with stricter language.
The FDA and the CDC recommended suspending administration of the shot, called Ixchiq, in individuals age 60 and older back in May after post-marketing reports of some serious adverse events, including at least two deaths, in recipients of the vaccine who were between the ages of 62 and 89.
The U.S. regulators’ restriction on Ixchiq in older adults followed a similar move by their European counterparts. And now, removal of the U.S. pause also follows a similar recommendation from the European Medicines Agency in July.
The FDA said it reached the decision after completing an updated benefit-risk assessment of Ixchiq, including in adults of all ages, in whom the vaccine has been approved since November 2023.
In parallel to ending the halt, the FDA has made several adjustments to Ixchiq’s label. While the original approval cleared the chikungunya virus (CHIKV) shot in individuals who were at “increased risk” of exposure to the mosquito-borne virus, the new label says it’s meant for those who are at “high risk” of exposure.
A new entry of “limitations of use” has been added to the label’s indications section, stating, among other things, that Ixchiq is “not advisable” for most U.S. residents traveling abroad because the risk of exposure to chikungunya is low.
The “decision to administer Ixchiq should take into consideration an individual’s risk of severe or chronic disease outcomes if infected with CHIKV and risks of serious, severe, or prolonged chikungunya-like illness caused by vaccination with Ixchiq, in addition to the risk of exposure to CHIKV,” the updated label shows.
As of Aug. 5, a CDC surveillance system called ArboNET has recorded 46 cases of chikungunya in the U.S., all labeled as travel-associated.
The updated prescribing information also includes warnings regarding reports of serious adverse events, especially in people above 65 years of age with one or more chronic medical conditions.
The Ixchiq update comes as a new wave of chikungunya outbreaks has caught the attention of the World Health Organization. The CDC has issued chikungunya-related travel alerts for outbreaks in Bolivia, Kenya, Madagascar, Mauritius, Mayotte, Réunion, Somalia, Sri Lanka and the southern Chinese province of Guangdong. The outbreak in Guangdong and the nearby Hong Kong has become China’s largest of chikunguya ever documented, with more than 7,000 cases reported since June.
In its travel warning, the CDC highlighted that two chikungunya vaccines are approved in the U.S. Besides Ixchiq, which is a live-attenuated vaccine, Bavarian Nordic’s virus-like particle vaccine Vimkunya was approved in February 2025 for use in people 12 years of age and above.
Bavarian Nordic is in the middle of a proposed acquisition by private equity shops Nordic Capital and Permira, although the Danish vaccine maker’s largest shareholder, pension fund ATP, has objected to the transaction.
Vimkunya is currently undergoing a new phase 3 trial in children 2 to 11 years of age, with results expected in the first half of 2028.
For its part, Valneva said the FDA is reviewing a potential extension of Ixchiq’s use to adolescents and inclusion of additional durability data. The shot received marketing authorization from the European Commission in April to also cover individuals 12 years of age and older.