Pfizer, Valneva announce positive phase 2 booster results of Lyme disease vaccine candidate

Valneva SE and Pfizer Inc. reported positive results from their VLA15-221 Phase 2 study of the Lyme disease vaccine candidate, VLA15. This study assessed the safety and immunogenicity of a second booster dose administered one year after the first. The vaccine showed a similar immune response and safety profile as the first booster, indicating its effectiveness for each Lyme season. VLA15 is the most advanced Lyme disease vaccine candidate, with two ongoing Phase 3 trials.

The study involved 560 participants across various age groups and demonstrated high seroconversion rates above 90% for all serotypes after the second booster. The vaccine's safety profile remained consistent with previous doses.

Pfizer and Valneva plan to submit applications for regulatory approval in 2026. VLA15 targets the outer surface protein A (OspA) of Borrelia burgdorferi, aiming to prevent Lyme disease by blocking bacterial transmission from ticks to humans.