Pfizer and France-based Valneva SE (Nasdaq: VALN)'s Lyme disease vaccine has entered formal European regulatory review, putting PF-07307405 on course to potentially become the first human vaccine against the tick-borne disease available in more than two decades. The European Medicines Agency (EMA) validated the MAA for the 6-valent OspA vaccine following Phase III VALOR data showing approximately 73–75% efficacy. No human Lyme disease vaccine is currently approved anywhere in the world, making this the first such candidate to reach EMA review.
The MAA submission is based on efficacy data from the Phase III VALOR ("Vaccine Against Lyme for Outdoor Recreationists") trial (NCT05477524), which reported more than 70% efficacy against confirmed Lyme disease in individuals aged five years and older. The vaccine was administered as four doses — at months 0, 2, and 5–9, followed by a fourth dose approximately one year later ahead of the second Lyme disease season. The companies said the vaccine was well tolerated, with no safety concerns identified.
The VALOR trial enrolled 9,437 participants aged five years and older, randomized 1:1 to receive PF-07307405 or saline placebo across sites in the US, Canada, and Europe. VALOR reported vaccine efficacy of 73.2% from 28 days after the fourth dose, although the analysis narrowly missed a prespecified statistical criterion after fewer Lyme disease cases accrued than expected. A second prespecified analysis, measuring efficacy from one day after dose four, showed 74.8% efficacy and met the statistical threshold.
PF-07307405 targets OspA, a lipoprotein expressed on Borrelia burgdorferi spirochetes within the Ixodes tick midgut. Vaccine-induced antibodies are ingested by the tick during feeding, binding to OspA on Borrelia inside the tick and inhibiting the bacterium's ability to exit the tick and infect the human host. The 6-valent formulation covers the six most prevalent OspA serotypes across Borrelia burgdorferi sensu lato species in both North America and Europe.