Health · Medical Research · 2 hrs ago
Ixchiq study finds antibodies persisted five years after one dose
Valneva says one dose of its Ixchiq vaccine left 94% of participants with high antibody levels after five years.
The finding came from a study of 221 healthy adults, and antibody levels were measured against the threshold for testing positive for immunity.
Ixchiq is one of the few vaccines available against chikungunya, a virus spread by Aedes aegypti mosquitoes that can cause fever and joint pain.
Longer-lasting immunity from one dose could help protect people against outbreaks that are difficult to predict.
The vaccine has faced restrictions after reports of serious side effects, including a death in Réunion during a major outbreak in 2025.
The European Union restored its authorization in July 2025, but France still advises against giving it to older people.
Ixchiq is also not for people with weakened immune systems, and the study findings concern antibodies rather than reported protection from illness.
Valneva said a study found that antibodies remained above the seropositivity threshold in most participants five years after one dose of its Ixchiq chikungunya vaccine.
The company reported that 94% of 221 healthy adults retained those antibody levels.
Valneva’s scientific director said lasting immunity after one dose could be a public-health advantage for a disease with hard-to-predict outbreaks.
The vaccine faced safety concerns in 2025, including reports of serious side effects and a death in Réunion.
The European Union reauthorized Ixchiq in July 2025, while France continued to advise against giving it to older people.
- Who
- Valneva announced the study results. The study included 221 healthy adults.
- What
- The study found that 94% of participants retained neutralizing antibody levels well above the seropositivity threshold five years after one dose of Ixchiq.
- When
- Valneva announced the results on November 10, 2026.
- Where
- Not stated
- Why
- The study assessed how long antibodies persisted after vaccination.
This story does not have two clearly opposing sides.
Ixchiq’s US license was suspended after four new cases of serious side effects were detected.
The European Union reauthorized the vaccine, judging that its side effects did not call its usefulness into question given the danger chikungunya poses to older people.
Valneva announced the five-year antibody study results.
- Participants
- 221 healthy adults
- Antibody persistence
- 94% retained levels above the seropositivity threshold
- Follow-up period
- Five years after one dose
- European Union
- Reauthorized Ixchiq in July 2025
- France
- Continued to advise against vaccination for older people
What people are saying
94% of the 221 healthy adults who participated in the study retained neutralizing antibody levels far above the seropositivity threshold five years after a single injection of the vaccine
For diseases such as chikungunya, whose epidemic outbreaks are difficult to predict, long-lasting immunity after the administration of a single dose is an important public-health advantage