Valneva Reports Positive Phase 2 Results For Lyme Disease Vaccine VLA15, Showing Strong Immune Response And Favorable Safety Six Months After Third Booster

Valneva SE, announced positive final immunogenicity and safety results from its Phase 2 study, VLA15-221, evaluating the Lyme disease vaccine candidate, VLA15. The data demonstrated a strong anamnestic immune response and favorable safety profile six months after a third booster dose (month 48) across all age groups, supporting the potential benefits of annual vaccination prior to each Lyme season. Valneva is developing VLA15 in collaboration with Pfizer, following an agreement signed in April 2020 for the vaccine’s development and commercialization.

Currently, no vaccines are approved for human use against Lyme disease, and VLA15 is the most advanced candidate in clinical development, with all vaccinations completed in the pivotal Phase 3 VALOR trial. According to the Centers for Disease Control and Prevention (CDC), around 476,000 people in the United States are diagnosed and treated for Lyme disease each year, while Europe reports approximately 132,000 cases annually. Pending positive Phase 3 results, Pfizer plans to submit a Biologics License Application (BLA) to the U.S. Food and Drug Administration and a Marketing Authorization Application (MAA) to the European Medicines Agency in 2026.

Juan Carlos Jaramillo, M.D., Chief Medical Officer of Valneva, said that the final Phase 2 data are consistent with previous findings and confirm the benefits of booster doses across all age groups. He highlighted that Lyme disease continues to expand geographically and represents a significant unmet medical need across the Northern Hemisphere. Each set of positive results brings the vaccine closer to availability for adults, adolescents, and children in endemic regions.

The study showed that an additional booster dose immediately increased antibody levels, which gradually declined over time but remained well above baseline at month 48, six months after the third booster at month 42. Two dosing schedules were compared, and antibody levels were higher with the three-dose primary vaccination schedule (Month 0-2-6) compared to the two-dose schedule. Geometric mean fold rises (GMFRs) from baseline ranged from 9.5-fold for Serotype 1 (ST1) to 15.6-fold for Serotype 2 (ST2) across all age groups in the three-dose schedule. The strongest responses were observed in children aged 5 to 11 years, with GMFRs ranging from 15.5-fold (ST1) to 28.5-fold (ST2).

These results support the use of the three-dose primary vaccination schedule and a yearly booster, as included in Phase 3 protocols. The safety and tolerability of VLA15 six months after the third booster were consistent with previous doses, with no safety concerns identified by the independent Data Monitoring Committee in any age group.