IXCHIQ, a living monovalent attenuated vaccine, obtained a centralized European MA on June 28, 2024.EyeEm Mobile GmbH / iStock / Getty Images Plus / via Getty Images
Résumé
The pharmacovigilance survey on IXCHIQ, vaccine against chikungunya, identified, on June 4, 2025 in France, 47 undesirable effects, including 18 serious and 3 deaths, mainly in subjects over 65 years of age and/or having comorbidities.
Among the 18 serious cases, 78 % (14/18) concerned subjects over 65 (median age: 76.5 years) and/or who presented comorbidities.
Serious symptoms mainly mentioned syndrome « chikungunya like ».
To date, 8 patients are restored, 7 are not, and 3 have died.
The link with the vaccine is judged “Very likely” For 1 death.
Death notification rates are estimated by the regional pharmacovigilance center at 8/100,000 doses overall, and 18/100,000 among those over 65.
Three signals require additional investigations:
- encephalopathy/encephalitis (n = 3);
- Fall between J1-J5 (n = 7);
- Thrombotic microangiopathy (n = 1).
Three events are under surveillance: the occurrence of renal failure, thrombocytopenia (n = 4), and misuse in immunocompromised patients.
Surveillance continues and the European re -evaluation of the vaccine is underway.
La Chikungunya vaccination campaign With the ixchiq powder and solvent vaccine for injection solution was launched on April 7, 2025 on Reunion Island [1].
Less than 3 weeks later, on April 25, 2025, due to the occurrence of 3 serious adverse effects (IS), including 1 death in subjects 65 and over, the High Authority for Health has spoken out in favor of revision of vaccination targets. Ixchiq was thus contraindicated in this age group temporarily pending its European re-evaluation (cf. Our article of June 3, 2025).
Have 2 May 2025, 43,400 doses of the IXCHIQ vaccine had been administered worldwide (France, other countries of the European Union, United States, Canada), 43 % (or 16 236 doses) To people aged 65 and over, considered at high risk of serious form in the event of chikungunya infection.
The vaccination campaign continued in Reunion, then in Mayotte (from May 28, 2025), targeting only people from 18 to 64 years old presenting At least a comorbidity.
Spontaneous notifications in pharmacovigilance : 47 cases of side effects including 18 graves
On July 2, 2025, the publication of the first results of the pharmacovigilance survey carried out by the Regional Pharmacovigilance Center (CRPV) of the European Hospital Georges-Pompidou (HEGP, Paris) made it possible to better characterize the IXs of the IXCHIQ [2,
Between March 7 and June 2, 2025, 47 cases of IS, 18 serious cases of which were reported throughout French territory, including 11 (23 %) in mainland France and 36 (77 %) in endemic or epidemic zone in Reunion or Martinique.
These declared cases mainly concerned subjects over 65:
- 55 % among non -serious cases (16 cases out of 29; median age: 66.5 years; extremes: 35 to 77 years);
- 78 % among serious cases (14 in 18 cases; median age: 76.5 years; extremes: 45 to 89 years).
Among the 29 “non -serious” cases, 10 (34 %) presented comorbidities. The IS described are mainly related to a systemic reactogenicity with a vaccine such as headache (13), arthralgia (12), fever (11), myalgia (8).
Among the 18 serious cases, 14 (78 %) presented comorbidities. IS mainly evoke a table « chikungunya like »similar to that of a serious form of infection by the virus (cf. Vidal monograph).
A “very likely” link with the vaccine for one of the three deaths
To date, out of the 18 patients who have presented a serious IS:
- 8 are restored or being recovered;
- 7 are not restored;
- 3 died (the latter were over 65 and presented other associated pathologies).
According to chronological and semiological criteria [4]a link with the vaccine seems “Very likely” For a case. For the other two: ” It was not possible to establish a link ».
According to the CRPV, the notification rates of fatal evolution cases are estimated at:
- 8 cases for 100,000 doses (or 1 case for 12,640 doses) if all of the administered doses are taken into account;
- 18 cases for 100,000 doses (or 1 case for 5,412 doses) in 65 and over.
Three potential signals being investigated
New or unusual side effects, suggesting a possible role in the vaccine, have also been highlighted:
- encephalopathy or encephalitis (n = 3), occurred in elderly people with comorbidities;
- Fall (n = 7) between J1 and J5 after vaccination, in a context of vagal discomfort and/or a fever and/or encephalopathy;
- Thrombotic microangiopathy (n = 1) whose first signs appeared from J2 after vaccination.
These 3 potential signals are the subject of additional investigations at European level.
Three events under surveillance
Three events are under surveillance:
- a kidney failure: In the event of postvaccinal fever in an elderly or fragile subject, an assessment of the renal function is recommended in order to correct any metabolic or hydroelectrolytic imbalances;
- a thrombocytopenia : 4 cases associated with a table chikungunya like have been reported;
- and misuse in a context of immunosuppression: remember that IXCHIQ, Living vaccine attenuated, is contraindicated in immunodeficiency or immunode-depressed people due to a medical disease or treatment.
Surveillance continues in connection with the European authorities. The reassessment of the benefit/risk balance of this vaccine by the European Pharmacovigilance (PRAC) Committee of the EMA is underway. To follow …
|
The risk factors for severe forms of infection by the chikungunya virus that causes hospitalization of more than 24 hours are:
The serious cases mainly affect those over 65 and under 3 months.
|
