Valneva Updates Safety Label of Chikungunya Virus Vaccine

Valneva has updated the Serious Adverse Events and the Warnings and Precaution sections of the prescribing information for the Chikungunya vaccine Ixchiq to include a warning about its use among people over the age of 60 with multiple underlying health conditions.

Ixchiq is indicated to prevent Chikungunya virus (CHIKV) in people 18 years of age and older who are at high risk of exposure to the virus. It contains a live, weakened version of the chikungunya virus and may cause symptoms similar to those of chikungunya disease. Chikungunya virus is a mosquito-borne viral disease spread by the bites of infected Aedes mosquitoes. It can cause fever, severe joint and muscle pain, headache, nausea, fatigue and rash. The joint pain is often debilitating and can persist for weeks to years.

Regulators have suggested that for U.S. travelers, the risk of exposure to CHIKV is low, and Ixchiq should be given when there is a significant risk of chikungunya infection. The vaccine is not recommended for people with weakened immune systems due to disease or immunosuppressive treatments.

The FDA has also lifted its pause on use of the vaccine in older people. In May 2025, the FDA and the CDC issued a safety communication to consider reports of serious adverse events from Ixchiq, including neurologic and cardiac events, in people who have received the vaccine.

As of May 7, 2025, 17 serious adverse events, including two that resulted in death, have been reported in people 62 through 89 years of age who received Ixchiq during postmarketing use globally. Six of these reports have been from the United States.

Europe and France have also paused the vaccine’s use to assess its safety. European authorities lifted their restriction on the use of Ixchiq in July, saying it should not be used in people with compromised immune systems.

In March 2025, France had responded to a chikungunya outbreak on the Island of La Réunion with a mass vaccination campaign of older people. At that time, there had been 8,600 cases of chikungunya, with almost 3,000 new cases during the week of March 3 to 9, 2025.

But on April 25, French regulators suspended the use of Ixchiq after three serious adverse events resulting in hospitalizations, including one death. All three people were over the age of 80 and had preexisting health conditions. At that point, Valneva had supplied 40,000 doses of Ixchiq to La Reunion. These adverse events were reported through the pharmacovigilance system set up by the French health authorities, and at the time causality had not been established.

Ixchiq was approved by the FDA in November 2023, initially for those over the age of 18, and U.S. regulators are reviewing data about extending the use for adolescents. In the European Union, regulators approved Ixchiq in June 2024, and in March 2025, the European Commission granted a label extension for adolescents 12 years of age and older.

In June, Valneva reported data from a phase 2 trial of the vaccine in children from the ages of 1 to 11. In the trial, 304 children were enrolled and randomized to receive one of two different doses. A strong immune response was seen in CHIKV-naïve children with a 96.5% seroresponse rate (full dose) at day 180. The vaccine was well tolerated in children, and no safety concerns were identified. A phase 3 trial in this population is expected to begin in the first quarter of 2026.