Overview

• Valneva was ordered to halt U.S. sales and shipments immediately, and its Paris-listed shares fell about 25% to 26%.
• FDA and company disclosures cite roughly 21 hospitalizations and three deaths in post-marketing reports, including one encephalitis death directly attributable to the vaccine strain.
• Regulators said Ixchiq appears to cause chikungunya-like illness in some recipients, with four additional serious cases reported recently, three in people aged 70–82 and one in a 55-year-old, all outside the United States.
• The suspension reverses an early August decision that had restored use with updated warnings for older adults, and FDA vaccine leaders signaled they intend to propose a full market withdrawal.
• Bavarian Nordic’s Vimkunya is now the only chikungunya vaccine approved in the U.S., while Valneva continues investigations, keeps access where licensed, and has not changed 2025 revenue guidance.