In response to the chikungunya epidemic in Réunion, a vaccination campaign targeting those most at risk of severe forms of this mosquito-borne disease will be implemented, health authorities announced on Wednesday.
The French National Health Authority, which was contacted urgently by the government, recommended that priority be given to vaccinating seniors over 65, adults with comorbidities (high blood pressure, diabetes, cardiovascular disease, etc.), and mosquito control workers on this French island in the Indian Ocean.
This advice will be followed by the health authorities who will "work on the operational implementation of this vaccination," the Ministry of Health told AFP, without specifying a timetable, confirming information from franceinfo.
To "limit serious cases and the health impact of the epidemic, exceptional funding" will be released "quickly" in order to "offer free vaccination to priority targets" in Reunion, the same source specified.
Since the Franco-Austrian manufacturer of the available vaccine, Valneva, has not applied for reimbursement from health insurance, the cost of the product, around 250 euros, remains in principle the responsibility of the patient.
The HAS will also soon decide on the use of the Vimkunya vaccine, developed by Bavarian Nordic.
The chikungunya outbreak, which began this summer, has intensified in recent weeks in Réunion, with 3,390 cases recorded since August 23, 2024, including 3,245 since the beginning of 2025, according to Public Health France. More than half of these are indigenous cases, infected by a mosquito present on the island.
While the health impact remains limited at this stage, with 13 hospitalizations but no serious cases or deaths reported, local and national authorities are monitoring it closely.
– “Peak around May” –
A generally benign viral illness, chikungunya causes a sudden fever accompanied by intense muscle and joint pain. However, complications—neurological, muscular, cardiovascular—and even death can occur, and symptoms can persist for more than three months.
To date, there is no curative treatment, but the first vaccine against chikungunya, Valneva's Ixchiq, was granted marketing authorization in Europe for adults in June.
Given the situation in Réunion, the HAS has recommended that priority be given to vaccinating populations at risk of severe and/or chronic forms and without a previous diagnosis of infection, given the significant efficacy expected in these categories and the "limited number of doses" available.
However, due to a lack of sufficient safety data, the use of Ixchiq – a live attenuated vaccine – is not recommended "at this stage" in pregnant women and remains "contraindicated in immunocompromised individuals."
Prior to the current outbreak, no cases of chikungunya had been reported in Réunion since 2010. A major epidemic there affected 260,000 people and caused 225 deaths between 2005 and 2006.
The epidemic should be "less severe than 20 years ago," Xavier Deparis, director of health monitoring at the Regional Health Agency (ARS), estimated a few weeks ago, while declaring himself "vigilant."
"We expect a peak around May, so we need to move quickly with preventive measures" and against mosquitoes that transmit the virus, because only "17% of the population of Réunion Island has, a priori, immunity against chikungunya," declared infectiologist Émilie Mosnier in mid-February, during a press conference of the ANRS-Emerging Infectious Diseases.
Even after vaccination, it is important to continue to combat larval breeding grounds and avoid bites by wearing protective clothing and using repellents and mosquito nets, health authorities insist.
Mosquito control operations have increased in Reunion Island in recent weeks, and 10 million sterile tiger mosquitoes coated with a biocide will be released in April in the south of the island - an experiment to try to stop reproduction.
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