Valneva SE (NASDAQ:VALN) reported positive five-year antibody persistence results for its single-dose chikungunya vaccine, IXCHIQ, confirming that the shot delivers lasting immune protection across diverse age groups in line with internal expectations.
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The findings reinforce the product’s differentiated profile and demonstrate its capacity to provide long-term protection through a single administration, mirroring outcomes seen with other live-attenuated vaccines.
Robust Five-Year Antibody Durability
Data from the VLA1553-303 trial revealed that 94% of the 221 evaluable adult participants maintained neutralizing antibody levels well above the seroresponse threshold five years post-vaccination.
Older adults aged 65 and above achieved immune persistence comparable to adults aged 18 to 64, recording similar geometric mean titers and seroresponse rates.
The Coalition for Epidemic Preparedness Innovations and the European Union’s Horizon Europe program funded the study.
Researchers will continue monitoring participants for up to 10 years to assess the vaccine’s lasting immune durability.
Real-World Evidence In Brazil
Alongside clinical monitoring, Valneva continues to collect real-world data through post-marketing programs.
Between February and October 2026, the Brazilian Ministry of Health and Instituto Butantan administered IXCHIQ to nearly 80,000 adults aged 18 to 59 during a Pilot Vaccination Strategy in Brazil.
In January, Valneva decided to voluntarily withdraw the biologics license application (BLA) and Investigational New Drug (IND) application for Ixchiq in the U.S.
In August 2025, the U.S. Food and Drug Administration (FDA) suspended the license for Ixchiq, citing four new reports of serious adverse events (SAEs) consistent with chikungunya-like illness.
VALN Price Action: Valneva shares were up 4.24% at $5.90 at the time of publication on Tuesday, according to Benzinga Pro data.
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