An outbreak of chikungunya, a viral disease spread via mosquito bites, continues to spread on the French island of Reunion, Report informs via Infectious Disease Special Edition (IDSE).
During the week of March 17-23, 2025, the territory had 5,832 confirmed cases, and more than 18,000 consultations with a healthcare provider about the virus, according to the Agence Régionale de Santé La Réunion (ARS). While the epidemic is widespread throughout the island, most cases occurred in the municipality of Le Tampon. The cities of Saint-Denis, Saint-Paul and Saint-Pierre are among the most affected areas of the territory.
In total, since August 2024, there have been 20,242 reported cases of chikungunya, 129 hospitalizations lasting more than 24 hours and two deaths. From March 17-23, 25 pregnant women and 17 infants were hospitalized after infection with chikungunya virus.
Of these, 14 newborns were hospitalized in pediatric ICUs or neonatal ICUs on the island. Twelve of the children were admitted to intensive care with encephalitis related to the transmission of the virus from mother to child. The other two children were infected more than seven days after birth; these infections were not the result of mother-to-child transmissions.
This highlights the particular importance of protecting pregnant women, newborns and infants, as they are not eligible for approved vaccines, according to ARS.
Valneva SE, a specialty vaccine company based in Saint-Herblain, France, has announced plans to provide 40,000 doses of its chikungunya vaccine (Ixchiq) to Reunion Island. Ixchiq was the first vaccine approved for chikungunya, and is approved in the United States, Europe, Canada and the United Kingdom for use in adults 18 years of age and older.
Recently, the European Medicines Agency adopted a positive opinion regarding recommending a label extension for the vaccine to be used in children 12 years of age and older.
“Chikungunya outbreaks spread rapidly, so it is crucial to vaccinate as many people as possible to help contain the virus,” Juan Carlos Jaramillo, MD, the chief medical officer of Valneva, said in a press release.
Vimkunya, a single-dose chikungunya vaccine developed by Bavarian Nordic A/S, also received FDA approval in February 2025. It is indicated for use in people 12 and older, and is now commercially available, as of March 18.
Reunion Island authorities are working to increase protective measures, particularly for pregnant women and children. These include the use of suitable mosquito repellants, installation of mosquito nets, wearing long clothing and eliminating stagnant water in and around homes.
