Record number of chikungunya cases in France, as US suspends French-made vaccine

Mainland France has seen an explosion of chikungunya outbreaks this summer and local officials are hunting down the tiger mosquitoes responsible for spreading the virus. Meanwhile, the United States has suspended the licence for a French-made vaccine against the virus following reports of serious side effects.

Mainland France has seen a record number of cases of chikungunya this summer because of the spread of the tiger mosquito, which carries the virus, and is now present nearly everywhere in the country.

Health authorities have recently focused on Vitrolles, a suburb of Aix-en-Provence in southern France, where authorities recorded 33 cases of the virus transmitted locally – the largest outbreak ever observed in mainland France.

Spreading beyond the tropics

A total of 27 outbreaks involving 154 cases have been recorded in mainland France this year, according to the national health agency SPF.

France's Reunion Island has been facing a deadly outbreak of the tropical disease since 2024, with one third of the population estimated to have been infected, according to the World Health Organisation (WHO). 

The virus has been spreading in mainland France as temperatures in northern Europe have warmed, and winters are no longer cold enough to kill off the tiger mosquitoes.

The mosquito, which also carries dengue fever, which is also on the rise, is now present in over 80 of France's 101 departments, and mosquito control measures are being stepped up in areas with infections.

Chikungunya virus outbreak kills six on France's Réunion Island

Vaccine suspended in US

Meanwhile, US health authorities have suspended the license for Ixchiq, a vaccine against chikungunya, made by the French company Valneva, following reports of "serious adverse events", particularly in elderly patients.

Valneva obtained US approval for the vaccine in 2023, but reports of side effects have prompted reviews, including by the European Medicines Agency this year.

"As we determine potential next steps, and as the clear threat of chikungunya continues to escalate globally, Valneva remains fully committed to maintaining access to our vaccine as a global health tool," chief executive Thomas Lingelbach said in a statement.

Ixchiq is one of just two vaccines against chikungunya approved for use in the US and in Europe.

Chikungunya is rarely fatal, though there is an increased risk of death for babies and the elderly, and symptoms, which include high fever and severe joint pain, are often debilitating.

In July, the WHO warned of the risks of a major chikungunya epidemic, calling for urgent action.

(with newswires)