Source: Reuters
Pfizer and Valneva SE reported that their experimental Lyme disease vaccine achieved 73.2% efficacy in a late-stage trial, reducing confirmed cases 28 days after the fourth dose. However, the study missed its primary statistical goal: the confidence interval reached only 15.8%, below the required 20%, largely due to fewer-than-expected infections during the trial. A secondary analysis conducted earlier did meet the requirement, offering some support for the vaccine’s effectiveness.
Despite the setback, Pfizer Inc. plans to proceed with regulatory submissions, expressing confidence in the overall data. Market reaction was mixed, with Valneva shares dropping sharply while Pfizer’s dipped slightly. Analysts suggest regulators may be lenient given the lack of an approved Lyme vaccine. The disease, transmitted by ticks, affects hundreds of thousands annually in the U.S. If approved, the vaccine could launch around 2027, addressing a significant unmet medical need.