FDA & CDC Recommend Pause in Use of Ixchiq Chikungunya Vaccine for Older Adults Due to Safety Concerns

Edited by: TJVNews.com

The U.S. Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC) have jointly recommended a pause in the use of the Ixchiq Chikungunya vaccine in individuals aged 60 and older following postmarketing reports of serious adverse events, including deaths, associated with the vaccine. The agencies announced the decision on May 7, 2025, as they launched an in-depth investigation into the vaccine’s safety profile in older populations.

According to the FDA and CDC, a total of 17 serious adverse events—ranging from neurological complications to cardiac episodes—have been reported globally among recipients between the ages of 62 and 89. These events were identified after the vaccine was introduced into wider clinical use and are now under scrutiny through the Vaccine Adverse Event Reporting System (VAERS), a national system co-managed by both agencies. Of those 17 reports, six came from within the United States. Two individuals have died, including one from encephalitis.

The vaccine, Ixchiq (Chikungunya Vaccine, Live), was approved by the FDA on November 9, 2023, for the prevention of chikungunya virus disease in adults aged 18 and older who are considered at elevated risk for exposure. It contains a live, attenuated form of the virus—intended to generate immune protection but potentially capable of mimicking the disease it seeks to prevent. According to prescribing information included with the vaccine, there is already a known risk of severe or prolonged chikungunya-like adverse reactions.

In the vaccine’s clinical trials, conducted in North America and involving approximately 3,500 adult participants, common side effects included headache, fatigue, muscle and joint pain, fever, nausea, and injection site tenderness. However, 1.6% of Ixchiq recipients experienced severe chikungunya-like reactions that disrupted daily life or necessitated medical care. Notably, two individuals in the trials required hospitalization due to these symptoms. Some adverse effects persisted for more than 30 days, signaling potential long-term risks.

The newly reported serious events, particularly in older recipients with preexisting chronic medical conditions, have heightened concerns. While causality has not yet been firmly established—VAERS data does not confirm a direct link between vaccination and the adverse events—federal health officials are moving swiftly to evaluate the risk.

Ixchiq has been distributed in approximately 80,000 doses worldwide since its approval, according to FDA data. The vaccine’s broader rollout was aimed at protecting travelers, military personnel, and residents in regions where the chikungunya virus is endemic, such as parts of South America, Africa, and Southeast Asia. Chikungunya infection can cause debilitating fever, joint pain, and, in rare cases, life-threatening complications.

In light of the emerging safety signals, the FDA has initiated a revised benefit-risk assessment for Ixchiq specifically in individuals 60 years of age and older. Until the review is completed, the FDA and CDC are recommending that use of the vaccine in this population be paused. Healthcare providers are being advised to avoid administering Ixchiq to older adults and to report any suspected adverse events through VAERS.

“The FDA and CDC are committed to transparency and public safety,” the agencies said in a joint statement. “As we continue to review all available data, we are taking this precautionary measure to protect individuals at potentially higher risk of severe reactions.”

The agencies emphasized that while no final determination has been made regarding the causality of the adverse events, the seriousness of the reports—especially the fatalities—requires a thorough and immediate response. They also stressed that they would keep the public informed as new findings emerge from the ongoing safety review.

This development serves as a critical reminder of the importance of robust postmarketing surveillance, particularly for live-virus vaccines, and may lead to revised labeling or additional precautions for certain patient populations if the concerns are substantiated.

The FDA and CDC are expected to issue further updates upon completion of their investigations, including any necessary changes to vaccine recommendations for high-risk groups. In the meantime, individuals who have received the vaccine and are experiencing persistent or severe symptoms are encouraged to seek immediate medical attention.