Pharmaceutical giants Pfizer and French company Valneva announced Monday that their experimental Lyme disease vaccine demonstrated over 70% effectiveness in advanced clinical trials.
The American drugmaker revealed plans to pursue U.S. regulatory approval for the vaccine, designated PF-07307405.
Currently, no approved vaccine exists to protect against Lyme disease, which spreads through bites from infected blacklegged ticks. The last available vaccine, GSK’s Lymerix, was pulled from the market in 2002 due to low consumer interest.
The Pfizer-Valneva vaccine demonstrated 73.2% effectiveness beginning 28 days following the fourth dose. Initially, the trial fell short of its primary objective because fewer Lyme disease cases occurred than researchers expected, creating limited data for analysis.
A subsequent planned analysis achieved the target threshold, showing 74.8% effectiveness. This result boosted Pfizer’s confidence “in the vaccine’s potential” as the company prepares “submissions to regulatory authorities.”
The U.S. Centers for Disease Control and Prevention reports that Lyme disease symptoms include fever, headache, exhaustion, and a distinctive skin rash known as erythema migrans. Without treatment, the infection can affect joints, heart function, and the nervous system.
Healthcare providers can successfully treat most Lyme disease cases using several weeks of antibiotic therapy.
The CDC calculates that approximately 476,000 Americans receive Lyme disease diagnosis and treatment annually, while about 132,000 cases occur yearly across Europe, according to the pharmaceutical companies.
Valneva previously indicated it anticipates Pfizer will bring the vaccine to market during the latter half of 2027 following regulatory approval.
