Pfizer and Valneva reported Phase III results for their Lyme disease vaccine showing roughly 70%+ efficacy but failing to meet a pre‑specified statistical threshold because fewer-than‑expected Lyme cases occurred in the study period. The companies attributed the missed statistical criterion to low case accrual yet said the safety profile and point estimates support regulatory filings. Investors reacted sharply to the uncertainty, creating a tricky regulatory path: the partners intend to press ahead with submissions despite the statistical miss. Analysts and regulators will need to weigh efficacy signals against the protocol’s prespecified analysis and the epidemiology that limited event rates.