FDA Suspends Valneva's Chikungunya Vaccine Ixchiq in US Amid Serious Side Effects Reports

The US FDA has halted the use of Valneva's chikungunya vaccine, Ixchiq, after reports of serious side effects in four individuals, including three aged 70-82 and one 55-year-old. Symptoms were consistent with those previously reported in clinical trials among older adults. Valneva is assessing the financial impact but has not revised its revenue forecast. Competitor Bavarian Nordic also operates in this field.

The U.S. Food and Drug Administration (FDA) has suspended the use of Valneva's chikungunya vaccine, Ixchiq, following reports of four serious adverse events (SAEs) [1]. Among the affected individuals, three were aged between 70 and 82, with the oldest requiring a two-day hospital stay. A 55-year-old individual also experienced side effects after receiving the vaccine [1]. Valneva stated that the symptoms observed are consistent with those previously reported during clinical trials, particularly among older adults [1].

The suspension follows the FDA's decision on August 6, 2025, to remove its recommended pause in the use of Ixchiq in individuals 60 years of age and older [2]. The suspension is based on updated VAERS data, which now includes four additional SAEs that occurred outside the United States [2]. Valneva is committed to upholding the highest safety standards and will continue to engage proactively with health authorities in all territories where Ixchiq is licensed [2].

Valneva is evaluating the potential financial impact of a permanent withdrawal of the Ixchiq license in the United States but is not modifying its revenue guidance at this time. Sales of Ixchiq contributed €7.5 million to the Company's €91 million total product sales in the first half of 2025 [2]. The company is also focused on continuing its efforts to provide the vaccine to all countries where it is licensed and to accelerate vaccine access in low- and middle-income chikungunya-endemic countries [2].

Danish company Bavarian Nordic is a competitor to Valneva in this field [1].

References:
[1] https://www.marketscreener.com/news/fda-halts-valneva-s-chikungunya-vaccine-ixchiq-in-the-us-after-reports-of-serious-side-effects-ce7c50dbde80f32c
[2] https://www.manilatimes.net/2025/08/25/tmt-newswire/globenewswire/valneva-announces-fdas-decision-to-suspend-license-of-chikungunya-vaccine-ixchiq-in-the-us/2172953