Pfizer Lyme vaccine shows more than 70% efficacy but misses key statistical goal
NBC News • • general
Key Points:
- Pfizer and Valneva reported that their Lyme disease vaccine showed over 70% efficacy in a late-stage trial, demonstrating 73.2% effectiveness starting 28 days after the fourth dose compared to placebo.
- Despite this, the trial missed its primary goal due to fewer-than-expected Lyme cases, with the first analysis showing 15.8% efficacy in the worst-case scenario, below the required 20%, though a second analysis met the threshold with 74.8% efficacy.
- Valneva's U.S.-listed shares dropped more than 35% in premarket trading following the announcement, while Pfizer's shares remained flat.
- Lyme disease currently has no approved vaccine since GSK discontinued its Lymerix shot in 2002; the disease affects hundreds of thousands annually in the U.S. and Europe and can cause serious health issues if untreated.
- Pfizer plans to submit the vaccine for regulatory approval with an expected launch in the second half of 2027, pending successful approval.
