• The US has suspended the Ixchiq vaccine license due to serious adverse side effects.
• Valneva reports a drop in shares following the FDA's suspension order.
• Experts warn of chikungunya's potential as a pandemic threat amid climate change.
• This year, Europe recorded 27 outbreaks, a new record for chikungunya.

US health authorities have suspended the license for the Ixchiq vaccine against the chikungunya virus after several reports of "serious adverse events." This decision was announced by the French manufacturer, Valneva, which obtained US approval for the vaccine in 2023. The FDA's suspension comes following a review prompted by reports of side effects, particularly concerning the vaccine's use in older patients, as per analyses by both the US authorities and the European Medicines Agency this year, according to Channel News Asia, South China Morning Post, and Le Monde.

Valneva indicated that the suspension of the license is effective immediately and noted specific cases where serious side effects occurred, particularly in individuals aged 70 to 82, affecting their health significantly. In light of the suspension, company CEO Thomas Lingelbach stated that despite reviewing potential next steps regarding the vaccine, Valneva remains committed to ensuring access to Ixchiq, viewed as a vital tool for global health, according to Channel News Asia, South China Morning Post, and Le Monde.

The financial ramifications of this suspension have prompted a significant market response, with Valneva's shares dropping more than 26% in early trading on the Paris Stock Exchange. The ixchiq vaccine was expected to generate revenue, contributing €7.5 million ($8.8 million) in sales during the first half of the year, which the company stated it would continue to monitor despite the suspension's impact, according to Channel News Asia, South China Morning Post, and Le Monde.

Public health experts are increasingly concerned about the chikungunya virus, which they suggest could pose significant pandemic risks due to climate change enabling its mosquito vectors to expand into new regions. Symptoms of chikungunya commonly resemble those of dengue fever and Zika virus, characterized by high fever and severe joint pain that can be debilitating. Although generally not fatal, there are increased death risks for vulnerable populations such as infants and the elderly. This year, the World Health Organization has highlighted the urgency for action against chikungunya amid alarming early warning signs, having observed a spike in cases, particularly in Europe where 27 outbreaks have been recorded, marking a new record, according to Channel News Asia, South China Morning Post, and Le Monde.