On May 9, 2025, the Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC) issued a joint statement pausing the use of IXCHIQ (live‑attenuated chikungunya vaccine) in individuals 60 years and older due to a group of patients who experienced serious adverse events after vaccine administration. As of May 7, 2025, 17 serious adverse events in individuals 62 to 89 years of age had been reported. Six of the cases were reported in the U.S. using the Vaccine Adverse Event Reporting System (VAERS). Details of the six U.S. cases were discussed at the April 2025 Advisory Committee on Immunization Practices (ACIP) meeting. All had at least one underlying chronic condition, and adverse events were either cardiac or neurologic in nature. Association with the vaccine was plausible but not definitively causal.
Following the ACIP meeting when reports from other countries surfaced, the FDA and CDC recommended a pause in the use of IXCHIQ for individuals 60 years of age and older while the FDA completes a revised benefit-risk assessment. An additional vaccine that protects against chikungunya is Vimkunya. Vimkunya is a recombinant vaccine that includes three proteins from chikungunya virus. The proteins, one capsid and two envelope proteins, assemble to look like the virus, called virus-like particles (VLP). Since the VLPs contain no genetic material, the vaccine cannot replicate or cause an infection. Vimkunya was licensed by the FDA through an accelerated approval process in February 2025 for individuals 12 years and older. The ACIP approved recommendations for receipt of a single dose among those 12 years and older who are traveling to an area with a chikungunya outbreak, as well as for laboratory workers who may encounter the virus through their work. Adolescents and adults traveling to or moving to an area with an elevated risk for chikungunya may also consider vaccination.
Providers should continue to report concerns to VAERs, and public updates are likely to follow upon completion of the safety review.
On May 9, 2025, the Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC) issued a joint statement pausing the use of IXCHIQ (live‑attenuated chikungunya vaccine) in individuals 60 years and older due to a group of patients who experienced serious adverse events after vaccine administration. As of May 7, 2025, 17 serious adverse events in individuals 62 to 89 years of age had been reported. Six of the cases were reported in the U.S. using the Vaccine Adverse Event Reporting System (VAERS). Details of the six U.S. cases were discussed at the April 2025 Advisory Committee on Immunization Practices (ACIP) meeting. All had at least one underlying chronic condition, and adverse events were either cardiac or neurologic in nature. Association with the vaccine was plausible but not definitively causal.
Following the ACIP meeting when reports from other countries surfaced, the FDA and CDC recommended a pause in the use of IXCHIQ for individuals 60 years of age and older while the FDA completes a revised benefit-risk assessment. An additional vaccine that protects against chikungunya is Vimkunya. Vimkunya is a recombinant vaccine that includes three proteins from chikungunya virus. The proteins, one capsid and two envelope proteins, assemble to look like the virus, called virus-like particles (VLP). Since the VLPs contain no genetic material, the vaccine cannot replicate or cause an infection. Vimkunya was licensed by the FDA through an accelerated approval process in February 2025 for individuals 12 years and older. The ACIP approved recommendations for receipt of a single dose among those 12 years and older who are traveling to an area with a chikungunya outbreak, as well as for laboratory workers who may encounter the virus through their work. Adolescents and adults traveling to or moving to an area with an elevated risk for chikungunya may also consider vaccination.
Providers should continue to report concerns to VAERs, and public updates are likely to follow upon completion of the safety review.