The Ixchiq vaccination against the chikungunya virus has been halted by US health officials due to reports of “serious adverse events”, according to the drug’s French manufacturer on Monday.
Ixchiq is one of only two vaccines licensed by the US Food and Drug Administration for the mosquito-borne virus, which is primarily found in tropical and subtropical climates but has lately been discovered in countries around the globe.
Valneva, a French company, won US approval for the vaccine in 2023, but reports of side effects have spurred assessments, particularly of its use in older people, including by the European Medicines Agency this year.
“The suspension of the licence is effective immediately,” Valneva said of the FDA order issued Friday, citing four additional cases of serious side effects, three of which involved people aged 70 to 82.
“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.
According to public health experts, chikungunya might pose a future pandemic threat as climate change drives the mosquitos that spread it into new areas.
The symptoms are similar to those of dengue fever and Zika virus, with a high temperature and severe joint pain that can be debilitating and last for many days.
Chikungunya is rarely fatal, but newborns and the elderly are especially vulnerable.
In July, the World Health Organisation issued a warning about the dangers of a significant chikungunya outbreak, urging immediate action.
The organisation said it was seeing the same early warning signs as a large outbreak two decades ago, which swept over the Indian Ocean before spreading globally and infecting nearly half a million people.
So far this year, Europe has witnessed 27 chikungunya outbreaks, setting a new record, according to the European Centre for Disease Prevention and Control.
