The National Agency for Medicines Safety (ANSM) published the first results of the survey on the undesirable effects of the IXCHIQ vaccine against chikungunya.
Three deaths and new side effects reported
According to the ANSM, between March 7 and June 2, 2025, “47 cases of side effects have been declared “of which “18 serious cases “. In half of these serious cases, a causal link was considered “possible” or “very likely” with the IXCHIQ vaccine, specify the health authorities in their synthesis made public this Wednesday.
The agency also reports that “Three deaths were reported in patients over 65 with comorbidities “. For one of them, she adds:
“A link between the IXCHIQ vaccine and one of the deaths seems very likely, given the chronology, the symptoms of the patient and the results of the biological examinations collected. To date, it is not possible to establish a link between the vaccine and the two other deaths”.
Other unusual effects are also under surveillance: 3 cases of encephalopathy or encephalitis, 7 cases of remote fall in vaccination and a case of thrombotic microangiopathy have been reported. These signals are currently being investigated at European level.
Cases of misuse in question
Beyond undesirable effects, the ANSM also noted errors in the administration of the IXCHIQ vaccine:
“The pharmacovigilance survey also reports on the administration of the vaccine to possibly immunocompromised patients. These are reports of undesirable effects following misuse”.
The vaccine, mainly administered in Reunion, is the subject of reinforced follow -up:
“The majority of undesirable effects (77 %) were reported by the La Réunion region, where the vaccination campaign started as soon as the vaccine is made.”
A vaccination suspended in those over 65
Faced with these reports, the French health authorities decided, from the April 26, 2025of no longer recommend vaccination of people aged 65 and overwhatever their medical situation. This decision was made pending the additional assessment of the benefit/risk balance of the vaccine in this population.
To date, vaccination remains authorized for adults aged 18 to 64 presenting a high risk of serious form of chikungunya.
Finally, the decision of a possible modification of the framework for the use of the vaccine will be played on a European scale. The ANSM specifies that: “The re -evaluation of the benefit/risk balance of this vaccine by the European Pharmacovigilance (PRAC) Committee of the EMA is underway “.