Key takeaways:
- The world’s first chikungunya vaccine has been related to 17 critical opposed occasions and two deaths.
- U.S well being officers really useful pausing vaccination amongst adults aged 60 years and older.
The CDC and FDA this week really useful that clinicians cease giving individuals aged 60 years or older the world’s first chikungunya vaccine whereas they examine opposed well being occasions related to the shot.
The vaccine “incorporates a dwell, weakened model of the chikungunya virus and will trigger signs much like these of chikungunya illness,” the U.S. well being companies mentioned in a joint press launch. “A few of the post-marketing stories embody opposed occasions which might be according to extreme issues of chikungunya illness, leading to hospitalization.”
The advice is predicated on stories of 17 critical opposed occasions globally, together with two deaths, amongst individuals aged 62 to 89 years who obtained the vaccine.
The European Medicines Company (EMA) can be reviewing using the vaccine amongst adults aged 65 years or older and has quickly restricted giving the vaccine to individuals in that age group.
Among the many 17 stories of opposed occasions, the FDA and CDC mentioned six got here from the U.S.
In line with the EMA, each deadly instances occurred on Reunion Island, a French division within the Indian Ocean — one in a person aged 84 years who developed encephalitis and the opposite in a person aged 77 years with Parkinson’s illness whose issue swallowing might have triggered aspiration pneumonia.
A vaccination marketing campaign on the island prioritized individuals aged 65 years or older with comorbidities till April 25, when France’s nationwide public well being company suspended its suggestion for the vaccine, known as Ixchiq, for that age group so it might examine the 2 deaths, in line with Valneva, which manufactures the vaccine. The marketing campaign continues for individuals aged 12 to 64 years.
The EMA mentioned that, along with individuals aged 65 years or older, the vaccine also needs to not be given to anyone with a weakened immune system because of illness or medical therapy.
“Individuals with a weakened immune system are at higher danger of getting issues from vaccines containing dwell attenuated viruses, no matter age,” EMA officers mentioned.
The FDA authorised the vaccine in November 2023 for individuals aged 18 years or older who’re at excessive danger for publicity to the virus, which is unfold by bites from contaminated Aedes mosquitoes. As a result of the approval got here underneath an accelerated approval course of, the FDA additionally required a section 4 post-marketing security research.
The EMA authorised the vaccine in June 2024, making it obtainable in Austria, Belgium, Denmark, Finland, France, Germany, Luxembourg, the Netherlands, Norway and Sweden.
Upwards of 80,000 doses of the vaccine have been distributed globally, the FDA mentioned, with a bit of greater than 43,000 individuals thus far receiving photographs, in line with the EMA.
The FDA approval was primarily based on two medical trials in North America with roughly 3,500 individuals aged 18 years or older, certainly one of which included testing the vaccine in opposition to a placebo, the company mentioned.
In line with the company, extreme chikungunya-like opposed reactions occurred in 1.6% of vaccine recipients throughout the two research. Some recipients additionally skilled opposed reactions for at the least 30 days, and two of them had been hospitalized with extreme opposed reactions.
Valneva chief medical officer Juan Carlos Jaramillo, MD, mentioned in a press launch that the corporate continues to see a optimistic risk-benefit of the vaccine to most individuals at higher danger for chikungunya publicity, noting that the CDC, FDA and EMA have, for probably the most half, retained their suggestions for different age teams.
“We’ll proceed participating proactively with the worldwide regulatory authorities whereas these necessary investigations proceed over the approaching months,” Jaramillo mentioned.
References:
- CDC. Chikungunya virus: Chikungunya vaccine data for healthcare suppliers. https://www.cdc.gov/chikungunya/hcp/vaccine/index.html. Up to date Could 10, 2025. Accessed Could 13, 2025.
- EMA. Ixchiq: Chikungunya vaccine (dwell). https://www.ema.europa.eu/en/medicines/human/EPAR/ixchiq#authorisation-details. Final up to date April 9, 2025. Accessed Could 13, 2025.
- EMA begins evaluation of Ixchiq (dwell attenuated chikungunya vaccine). https://www.ema.europa.eu/en/information/ema-starts-review-ixchiq-live-attenuated-chikungunya-vaccine. Printed Could 7, 2025. Accessed Could 13, 2025.
- FDA and CDC suggest pause in use of Ixchiq (chikungunya vaccine, dwell) in people 60 years of age and older whereas postmarketing security stories are investigated. https://www.fda.gov/vaccines-blood-biologics/safety-availability-biologics/fda-and-cdc-recommend-pause-use-ixchiq-chikungunya-vaccine-live-individuals-60-years-age-and-older. Printed Could 9, 2025. Accessed Could 13, 2025.
- Valneva offers replace following European Medicines Company announcement on use of Ixchiq in aged. https://valneva.com/press-release/valneva-provides-update-following-european-medicines-agency-announcement-on-use-of-ixchiqin-elderly/. Printed Could 7, 2025. Accessed Could 13, 2025.
- Valneva offers replace on really useful use of Ixchiq by aged people in the US. https://valneva.com/press-release/valneva-provides-update-on-recommended-use-of-ixchiq-by-elderly-individuals-in-the-united-states/. Printed Could 12, 2025. Accessed Could 13, 2025.
Perspective
This pause parallels one other dwell arboviral vaccine, yellow fever, the place there’s a precaution for individuals aged 60 years or older. No different live-attenuated vaccines are at present in routine use on this age cohort in the US. Immunosenescence impacts older individuals’ capability to adequately management replication of all dwell attenuated vaccine viruses.
A priority of some consultants is that the youthful, more healthy individuals are additionally getting some systemic vaccine-induced viral irritation within the CNS and/or joints however are younger sufficient to flee encephalopathy. FDA and CDC warning is definitely merited given the approval in February 2025 of an efficient non-live chikungunya vaccine (Vimkunya, Bavarian Nordic) which may be very effectively tolerated.
Many journey medication consultants I’ve spoken to would suggest avoidance of a dwell viral chikungunya vaccine in any age group till all these extreme opposed occasions are labored out. This isn’t like yellow fever vaccines the place there isn’t a alternative — the Advisory Committee on Immunization Practices voted on April 16 to suggest Vimkunya to all teams aged 12 years or older. [Editor’s note: The CDC has not yet signed off on this recommendation.]
David O. Freedman, MD, FIDSA
Professor of infectious ailments
College of Alabama at Birmingham
Disclosures: Freedman stories no related monetary disclosures.
