US approves first vaccine against chikungunya virus — drug regulator

WASHINGTON, United States — US health authorities on Thursday approved the world's first vaccine for chikungunya, a virus spread by infected mosquitoes that the Food and Drug Administration called "an emerging global health threat."

The vaccine, developed by Europe's Valneva which will be marketed under the name Ixchiq, was approved for people 18 and over who are at increased risk of exposure, the FDA said.

Ixchiq's green-light by the US drug regulator is expected to speed the vaccine's rollout in countries where the virus is most prevalent.

Chikungunya, which causes fever and severe joint pain, is most prevalent in tropical and subtropical regions of Africa, southeast Asia and part of the Americas. 

"However, chikungunya virus has spread to new geographical areas causing a rise in global prevalence of the disease," the FDA said, reporting more than 5 million cases in the past 15 years.

"Infection with chikungunya virus can lead to severe disease and prolonged health problems, particularly for older adults and individuals with underlying medical conditions," senior FDA official Peter Marks said in a statement.

"Today's approval addresses an unmet medical need and is an important advancement in the prevention of a potentially debilitating disease with limited treatment options."

The vaccine is injected in one dose and contains a live, weakened version of the chikungunya virus, as is standard with other vaccines.

Two clinical trials were carried out in North America on 3,500 people. Headache, fatigue, muscle and joint pain, fever and nausea were commonly reported side effects.

Serious reactions were reported in 1.6 percent of Ixchiq recipients in the trials, with two requiring hospitalization.