Paris (France) (AFP) – The Ixchiq vaccine against chikungunya is effective up to five years after the application of a single dose, the Franco-Austrian laboratory Valneva, which manufactures it, announced on Tuesday.

First modification: 11/10/2026 - 12:21

"94% of the 221 healthy adults who participated in the trial maintained levels of neutralizing antibodies well above the seropositivity threshold five years after a single injection of the vaccine," according to the pharmaceutical group.

The Ixchiq vaccine is one of the few available against chikungunya, a viral disease transmitted between humans by the bite of a mosquito that causes fever and joint pain.

"For diseases such as chikungunya, whose epidemic outbreaks are difficult to predict, a long-lasting persistence of immunity after the administration of a single dose constitutes an important public health advantage," said Hanneke Schuitemaker, scientific director of Valneva, quoted in a statement.

But this vaccine faced difficulties in 2025.

In the United States, its license was suspended last year when four new cases of serious side effects were detected, amid growing skepticism about vaccines in the Donald Trump government's health policy.

In France, its deployment had been interrupted in overseas territories due to several cases of serious effects among elderly people.

At least one person died in La Réunion, an overseas island hit in 2025 by a strong chikungunya epidemic.

The vaccine was suspended for those over 65 years of age in France, and then in the European Union.

The EU authorized the vaccine again in July 2025, considering that the side effects do not call into question its usefulness against a disease that is particularly dangerous for older people. However, France still recommends not applying it to older adults.

Ixchiq is also contraindicated for people with an immune system weakened by illness or medical treatment.

© 2026 AFP

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