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Promising phase 3 results bring Lyme disease vaccine closer to reality
Pfizer and Valneva announced positive topline results from the phase 3 VALOR trial of their investigational Lyme disease vaccine candidate, PF‑07307405 (LB6V, formerly VLA15), marking a major milestone toward the first approved human vaccine for Lyme disease.
In the large, multinational VALOR study involving participants ≥5 years of age, the 6‑valent OspA‑based vaccine demonstrated strong efficacy—approximately 73% to 75%—in reducing confirmed Lyme disease cases during the second tick season following a four‑dose regimen. While the trial’s primary statistical endpoint was narrowly missed due to fewer‑than‑expected cases overall, a key prespecified analysis met confidence interval criteria, supporting the vaccine’s clinically meaningful protection.
The vaccine candidate was generally well tolerated, with no new safety concerns identified at the time of analysis. Based on the data, Pfizer plans to advance regulatory submissions in collaboration with Valneva.
Source:
Pfizer and Valneva announce Lyme disease vaccine candidate demonstrates strong efficacy in phase 3 VALOR trial. [News release]. 2026. https://www.pfizer.com/news/press-release/press-release-detail/pfizer-and-valneva-announce-lyme-disease-vaccine-candidate
