Pfizer and Valneva have initiated a phase 3 study evaluating the efficacy, safety and immunogenicity of VLA15, an investigational Lyme disease vaccine candidate.

VLA15 is a 6-valent protein subunit vaccine that targets the outer surface protein A (OspA) of Borrelia burgdorferi, the bacteria that causes Lyme disease. The vaccine covers the most common OspA serotypes that are prevalent in North America and Europe.

The randomized, placebo-controlled VALOR study ( Identifier: NCT05477524) will enroll approximately 6000 participants 5 years of age and older. The study is being conducted at up to 50 sites located in areas where Lyme disease is highly endemic, including Finland, Germany, the Netherlands, Poland, Sweden and the United States.

Participants will be randomly assigned to receive 3 doses of either VLA15 180µg or saline placebo as a primary vaccination series at about 0, 2, and between 5 to 9 months (at a time of year such that the primary series is completed before the peak Lyme disease season), followed by 1 booster dose of VLA15 or placebo approximately 12 months later (prior to the beginning of the second Lyme disease season).

“With increasing global rates of Lyme disease, providing a new option for people to help protect themselves from the disease is more important than ever,” said Annaliesa Anderson, PhD, Senior Vice President and Head of Vaccine Research & Development at Pfizer. “We hope that the data generated from the phase 3 study will further support the positive evidence for VLA15 to date, and we are looking forward to collaborating with the research sites across the US and Europe on this important trial.”


Pfizer and Valneva initiate phase 3 study of Lyme disease vaccine candidate VLA15. News release. Pfizer Inc and Valneva SE. Accessed August 9, 2022.