The European Medicines Agency’s (EMA) Pharmacovigilance Risk Assessment Committee (PRAC) has recommended restricting use of the chikungunya vaccine Ixchiq to people at high risk for infection after a routine safety review in which serious adverse events, including hospitalization and death, were evaluated against the vaccine’s benefit-risk balance.

The committee has also endorsed a direct healthcare professional communication to alert clinicians to the updated recommendations.

About the Vaccine 

Ixchiq is a live-attenuated vaccine approved for individuals aged 12 years or older to protect against chikungunya disease. It contains a weakened strain of the chikungunya virus that prompts the immune system to produce targeted antibodies against future infection.

The vaccine is administered as a single intramuscular injection. Recipients should be advised that personal protection measures against mosquito bites remain important even after vaccination.

Restriction Follows Serious Adverse Events 

Known serious side effects occur mainly in adults aged 65 years or older and in people with multiple underlying chronic medical conditions, although complications have also been reported in younger, otherwise healthy adults. 

Reported events include severe or prolonged chikungunya-like reactions, deterioration of general condition including malaise and decreased appetite, exacerbation of pre-existing disease, and neurologic complications such as encephalopathy, encephalitis, aseptic meningitis, and confusion. Some cases resulted in hospitalization or death.

What This Means for Clinicians 

Ixchiq should now be used only in individuals aged 12 years and older who are at high risk of acquiring chikungunya infection, and only after careful consideration of potential benefits and risks. The vaccine remains contraindicated in immunocompromised patients and should not be co-administered with other vaccines.

Next Steps 

PRAC’s recommendations will be forwarded to the EMA’s Committee for Medicinal Products for Human Use, which will adopt the agency’s final opinion. Safety monitoring is ongoing, and clinical recommendations will be updated as further post-marketing data become available.