By FieldPulse Staff · March 23, 2026
Tags: vaccines, pfizer, phase-3, fda
The VALOR trial met its primary endpoint numerically but fell below the pre-specified statistical confidence interval, largely due to lower-than-expected Lyme disease case rates in the study population. Pfizer and Valneva say they still plan to pursue regulatory submissions.
Pfizer and Valneva announced Phase 3 results on March 23, 2026 for their Lyme disease vaccine candidate PF-07307405, a six-valent OspA-based vaccine. The data tell an unusual story: the vaccine worked — just not well enough to clear the pre-specified statistical bar, and for reasons largely outside the drug's control. The VALOR trial demonstrated 73.2% efficacy from 28 days after the fourth dose, and 74.8% from one day post-dose four. But the lower bound of the 95% confidence interval on the primary endpoint came in at 15.8%, below the pre-specified 20% threshold. The shortfall wasn't a safety