Pfizer and Valneva said their Phase 3 Lyme disease vaccine reduced cases by roughly 70–73% but missed the trial’s pre-specified statistical threshold. The companies acknowledged lower-than-expected infection rates during the study that tightened confidence intervals and said they will pursue regulatory submissions despite the primary endpoint miss. Public statements from both firms emphasize a favorable safety profile alongside the efficacy signal. Regulators will need to weigh the magnitude of observed protection against the statistical shortfall; the companies plan to present full datasets and supportive analyses. The situation raises questions about how agencies interpret underpowered vaccine trials when event rates fall below projections. The development matters for prevention of Borrelia burgdorferi infections across the U.S. and Europe and could influence CDC advisory timelines if regulators opt to review the dossier. Company filings and STAT coverage reported the efficacy figure and the companies’ intent to seek approval.