Chikungunya vaccine, live (cvx 317) FDA Alerts

FDA Update on the Safety of Ixchiq (Chikungunya Vaccine, Live)

August 6, 2025 -- On May 9, 2025, FDA issued a safety communication informing the public that the Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC) jointly recommended a pause in the use of Ixchiq (Chikungunya Vaccine, Live) in individuals 60 years of age and older while the Agencies undertook an investigation of postmarketing reports of serious adverse events, including neurologic and cardiac events, in individuals who have received the vaccine.

At the time of the May 9, 2025, recommended pause, FDA conveyed its intention to conduct an updated benefit-risk assessment for the use of Ixchiq in individuals 60 years of age and older. FDA has completed an updated benefit-risk assessment of Ixchiq, including for use in individuals 18 years of age and older. Based on the available data, and its benefit-risk assessment, FDA has removed the recommended pause in the use of Ixchiq in individuals 60 years of age and older and has approved updates to the Prescribing Information and Patient Information that it required of the company, Valneva Austria GmbH.

The November 9, 2023, approval of Ixchiq included a warning in the Prescribing Information informing that the vaccine may cause severe or prolonged chikungunya-like adverse reactions. Ixchiq contains a live, weakened version of the chikungunya virus and may cause symptoms in the vaccine recipient similar to those experienced by people who have chikungunya.

Key Points About the Required Labeling Updates

• The Indications and Usage statement has been revised from: Ixchiq is a vaccine indicated for the prevention of disease caused by chikungunya virus (CHIKV) in individuals 18 years of age and older who are at increased risk of exposure to CHIKV to: Ixchiq is a vaccine indicated for the prevention of disease caused by chikungunya virus (CHIKV) in individuals 18 years of age and older who are at high risk of exposure to CHIKV.

  As part of the Indications and Usage section, Limitations of Use has been added that states: “Vaccination with Ixchiq is not advisable for most U.S. travelers. For most U.S. travelers, the risk of exposure to CHIKV is low. The Centers for Disease Control and Prevention provides resources for assessing likelihood of exposure to CHIKV among travelers and laboratory workers (Chikungunya Vaccine Information for Healthcare Providers).

  The decision to administer Ixchiq should take into consideration an individual’s risk of severe or chronic disease outcomes if infected with CHIKV and risks of serious, severe, or prolonged chikungunya-like illness caused by vaccination with Ixchiq [see Warnings and Precautions (5.2) and Adverse Reactions (6.1 and 6.2)], in addition to the risk of exposure to CHIKV. For travelers, factors to consider include level of disease activity at destination, duration of travel or residence, and likelihood of exposure to mosquitoes.”

• The Warnings and Precautions section has been revised to reflect the serious adverse reactions that have been reported during postmarketing use with Ixchiq. Some of the postmarketing reports include adverse reactions that are consistent with severe complications of chikungunya, resulting in hospitalization, including encephalitis in a person who died. These reports suggest that individuals 65 years of age and older with one or more chronic medical conditions may have an increased risk for these serious adverse reactions following vaccination with Ixchiq.
• In the Adverse Reactions section, a new subsection, Postmarketing Experience, includes information about the adverse reactions that have been identified during postmarketing use with Ixchiq. These adverse reactions are consistent with serious chikungunya-like illness and include cardiac and neurological reactions.

Safety Monitoring Continues

With the November 9, 2023, approval of Ixchiq, FDA required the company to conduct a postmarketing study to assess the serious risk of severe chikungunya-like adverse reactions following administration of Ixchiq. The study is intended to be initiated by October 1, 2025.

Continuous monitoring and assessment of the safety of all vaccines remains an FDA priority. Suspected adverse events may be reported to the Vaccine Adverse Event Reporting System (VAERS), which is co-managed by FDA and CDC.

Source: FDA

FDA and CDC Recommend Pause in Use of Ixchiq (Chikungunya Vaccine, Live) in Individuals 60 Years of Age and Older While Postmarketing Safety Reports are Investigated

May 9, 2025 - The Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC) are recommending a pause in the use of Ixchiq (Chikungunya Vaccine, Live) in individuals 60 years of age and older while the Agencies investigate postmarketing reports of serious adverse events, including neurologic and cardiac events, in individuals who have received the vaccine.

As of May 7, 2025, 17 serious adverse events, including two that resulted in death, have been reported in individuals 62 through 89 years of age who received Ixchiq during postmarketing use globally. Six of these reports have been from the United States (U.S.). Most U.S. and foreign serious adverse events that have been reported to the Vaccine Adverse Event Reporting System (VAERS), co-managed by FDA and CDC, have been in individuals with underlying chronic medical conditions. Adverse events reported to VAERS may not be causally related to vaccination. Approximately 80,000 doses of Ixchiq have been distributed globally.

Ixchiq contains a live, weakened version of the chikungunya virus and may cause symptoms similar to those of chikungunya disease. Some of the postmarketing reports include adverse events that are consistent with severe complications of chikungunya disease, resulting in hospitalization; one person died from encephalitis. The FDA-approved Prescribing Information includes a warning to inform that the vaccine may cause severe or prolonged chikungunya-like adverse reactions.

On November 9, 2023, FDA approved Ixchiq for the prevention of disease caused by chikungunya virus in individuals 18 years of age and older who are at increased risk of exposure to chikungunya virus. The safety of Ixchiq was evaluated in two clinical studies conducted in North America in which about 3,500 participants 18 years of age and older received a dose of the vaccine, with one study including about 1,000 participants who received a placebo. The most commonly reported adverse reactions by vaccine recipients were headache, fatigue, muscle pain, joint pain, fever, nausea, and tenderness at the injection site.

In addition, although not commonly reported during the clinical studies, severe chikungunya-like adverse reactions that prevented daily activity and/or required medical intervention occurred in 1.6% of Ixchiq recipients and none of the placebo recipients. Two recipients with severe chikungunya-like adverse reactions were hospitalized. In addition, some recipients had prolonged chikungunya-like adverse reactions that lasted for at least 30 days.

FDA will conduct an updated benefit-risk assessment for the use of Ixchiq in individuals 60 years of age and older. In addition, FDA and CDC will continue the evaluation of postmarketing safety reports for Ixchiq. While the safety of Ixchiq for use in individuals 60 years of age and older is being further assessed, FDA and CDC are recommending a pause in use of the vaccine in this age group. FDA and CDC will update the public when the Agencies complete their evaluation of this safety issue.

Source: FDA