Pfizer and Valneva reported Phase 3 results showing their Lyme disease vaccine reduced infections by roughly 70–73% but failed to meet the trial’s pre‑specified statistical criterion. The partners said lower‑than‑expected Lyme case numbers during the study window drove the miss, while maintaining that the primary safety and efficacy signals were clinically meaningful. Both companies said they intend to proceed with regulatory submissions despite the statistical shortfall. Investors reacted sharply to the results, and regulatory reviewers will need to weigh the efficacy signal against the statistical outcome and study context when deciding whether to grant approval.