GlobeNewswire·Nov 9, 2026, 1:00 AM ET

Valneva Announces Positive Phase 2 Results for Tetravalent Shigella Vaccine Candidate S4V2

Valneva announced positive Phase 2 results for S4V2, the world's most advanced tetravalent bioconjugate Shigella vaccine candidate.
The infant trial (S4V02) in Kenya evaluated 110 nine-month-olds & found a favorable safety profile with mild-to-moderate adverse events.
S4V2 induced statistically significant increases in anti-LPS IgG antibodies for all four Shigella serotypes in infants, with titers peaking after the second dose.
Antibody levels remained above baseline six months post-vaccination in the infant trial, though further dose optimization is needed.
The controlled human infection model (CHIM) trial (S4V03) in the US involved 120 healthy adults & met its primary endpoint with a significant reduction in S. sonnei shigellosis incidence.
Participants in the CHIM trial received two doses of S4V2 or placebo one month apart before being challenged with the S. sonnei 53G strain.
Shigellosis is the second leading cause of fatal diarrheal disease globally, causing an estimated 165 million infections & 600,000 deaths annually.
The FDA granted Fast Track designation to S4V2 in 2024 due to its potential to address this serious unmet medical need.
LimmaTech sponsored both trials, with the infant trial receiving funding support from the Gates Foundation.
Valneva is currently analyzing complete datasets from both trials to determine the optimal path forward for future clinical development.