U.S. CDC Confirms Chikungunya Vaccine's 97% Seroresponse Rate

With over 402,000 Chikungunya virus (CHIKV) cases and 180 related deaths already reported this year in the Region of the Americas, a team of vaccine experts today presented very positive seroresponse rate data of the only approved vaccine.

On October 23, 2024, Susan Hills, MBBS MTH CDC Lead, Chikungunya Vaccines Work Group Arboviral Diseases Branch Division of Vector-Borne Diseases, led a review of the IXCHIQ® vaccine.

This U.S. CDC Advisory Committee on Immunization Practices (ACIP) presentation confirmed the long-term persistence trial is ongoing and has reported a seroresponse rate of 97% two years since the last dose.

This study's monitoring is scheduled to continue for 10 years to determine whether an IXCHIQ booster dose is needed, given the extensive Chikungunya outbreak in 2024.

Edwin Asturias, M.D., Chair, ACIP Chikungunya Vaccines Work Group, added that no safety signals have been reported since the U.S. FDA approved this vaccine in 2023. 

Additionally, Dr. Asturias commented, 'Some recommendations have been developed, and others are under development, for using chikungunya vaccines among U.S. persons at risk of chikungunya, including travelers, laboratory workers, and residents of U.S. territories and states with risk of transmission.'

Previously, the ACIP discussed the cost-effectiveness of IXCHIQ among adults living in U.S. territories where CHIKV cases are being reported.

Unfortunately, over 100 countries have confirmed locally acquired CHIKV infections in the past year. This means international travelers have a greater health risk than ever when visiting these countries.

And some are bringing Chikunynga home with them.

"The Chikungunya virus, an alphavirus spread by mosquitoes, leads to acute febrile polyarthralgia, inflammatory arthritis, acute skin eruptions, and other systemic symptoms. IXCHIQ, a live virus vaccine, is contraindicated for individuals with immunosuppression," stated Duellyn Pandis, DNP, APRN, FNP-C, CEO of Passport Health - Tampa.

As of Week #41, the CDC reported 131 travel-related chikungunya cases in people diagnosed in states such as Massachusetts (18), California, and Texas.

To increase access to this protective vaccine, Valneva SE, which produces IXCHIQ, has already secured approval in Canada, Europe, and the Virgin Islands. Brazil is currently reviewing a marketing application.

In the U.S., IXCHIQ is commercially available at most travel clinics and pharmacies.