EMA Initiates Review of Chikungunya Vaccine Ixchiq Safety

The European Medicines Agency (EMA) has commenced a safety review of the Chikungunya vaccine Ixchiq, developed by Valneva. This decision was announced on May 7, following reports of serious adverse effects observed in older individuals post-vaccination.

Ixchiq is a live attenuated vaccine that received approval for use in endemic regions and for travelers in June 2024. It has been available in Germany since March 2025, with approximately 43,400 doses administered to date.

According to the EMA's Pharmacovigilance Risk Assessment Committee (PRAC), 17 serious adverse events have been reported globally among individuals aged 62 to 89. Among these incidents, two fatalities were recorded. One involved an 84-year-old man who developed encephalitis, while the other concerned a 77-year-old man with Parkinson's disease, whose worsening swallowing difficulties may have led to aspiration pneumonia. Both cases occurred in the French overseas department of La Réunion, where a vaccination campaign is currently underway due to an outbreak of Chikungunya.

The EMA acknowledges that many individuals who experienced serious adverse events had pre-existing health conditions. The potential causal relationship between these events and the vaccine remains unclear. In light of these findings, the PRAC has recommended temporarily suspending the use of Ixchiq in individuals aged 65 and older. Vaccination can continue for younger adults, provided there are no other medical contraindications.

Furthermore, the EMA advises that individuals with weakened immune systems should not receive live vaccines such as Ixchiq, regardless of age, due to an increased risk of complications.