The biotech companies are recruiting about 6,000 participants age 5 and older at up to 50 sites in areas of Europe and the US where Lyme disease is endemic, they said Monday in a news release.
The participants will get three doses of the vaccine, called VLA15, or a placebo, followed by a booster dose.
"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," Annaliesa Anderson, senior vice president and head of vaccine research and development at Pfizer, said in the news release.
VLA15 is the only Lyme vaccine in clinical development, Pfizer said in the statement. It targets the bacteria Borrelia burdorferi, the main cause of the tick-borne disease, and has "demonstrated a strong immune response and satisfactory safety profile in pre-clinical and clinical studies so far."