​The Chikungunya virus is transmitted to humans by a bite from an infected tiger mosquito. The virus causes fever and affects the joints, causing highly disabling pain. Existing treatments are only symptomatic, which is why it is necessary to develop an effective vaccine.

Several vaccine candidates have been developed within the framework of European project ICRES[1], three of which have just been tested by a team from the François-Jacob Biology Institute. After demonstrating their efficacy on murine models, they were tested on preclinical models of non-human primates. "We worked on a vaccine designed from an attenuated strain of Chikungunya (Δ5nsP3), and on two non-replicative viruses (DNA, MVA[2]) provided by our Swedish and Spanish partners" said Pierre Roques, a researcher on viral diffusion at the François-Jacob Institute. By inducing the production of an antiviral cellular response and a strong antibody response that neutralizes wild-type virus replication within the body, all three vaccines have proven effective in protecting against exposure to African and Asian viruses. "No clinical sign typically associated with chikungunya appeared (no inflammation or fever) until 10 months after vaccination with Δ5nsP3," Roques said. "Also, no side effect was observed during follow-up, which attests the safety of the products."