Pfizer Valneva Lyme Disease Vaccine Candidate Clears EMA Application Review Milestone

Pfizer Valneva Lyme disease vaccine candidate has cleared a key regulatory checkpoint in Europe, with the European Medicines Agency validating the companies’ Marketing Authorization Application and formally opening its scientific review. Pfizer Inc. (NYSE: PFE) and Valneva SE (Nasdaq: VALN; Euronext Paris: VLA) announced on August 14, 2026 that the EMA has accepted the MAA filing for PF-07307405, a 6-valent outer surface protein A (OspA)-based vaccine candidate designed to prevent Lyme disease, the most common vector-borne illness in the Northern Hemisphere.

The submission rests on favorable data from the Phase 3 VALOR trial, short for “Vaccine Against Lyme for Outdoor Recreationists,” which enrolled 9,437 participants aged five years and older across high-incidence sites in the United States, Canada, and Europe. Topline results showed efficacy of more than 70% in preventing Lyme disease cases, and the companies reported no safety concerns emerged during the study. Trial participants received four doses on a staggered schedule, with the first three administered at months 0, 2, and 5-9, followed by a fourth booster roughly a year later, timed to precede the following tick season.

Annaliesa Anderson, Ph.D., Senior Vice President and Chief Vaccines Officer at Pfizer, said she was proud of the progress made on the program and described the opportunity to bring what would be the first vaccine of its kind to Europe. She noted that Lyme disease affects more than 100,000 people across the region each year and, left untreated, can progress into complications involving the skin, joints, nervous system, and heart. Thomas Lingelbach, CEO of Valneva, called the MAA validation a major milestone given that more than 200 million people live in areas of Europe where Lyme disease risk is present. Both executives framed the milestone as validation of a partnership that has run since 2020, with the Pfizer Valneva Lyme disease vaccine now positioned as the most clinically advanced candidate of its kind anywhere in the world.

Pfizer Valneva Lyme Disease Vaccine Candidate Built on Phase 3 VALOR Efficacy Data

The Pfizer Valneva Lyme disease vaccine program targets OspA, a surface protein expressed by Borrelia burgdorferi, the bacterium that causes Lyme disease. The mechanism is unusual among vaccines: rather than acting only within the human body, antibodies generated by vaccination are ingested by a feeding tick along with its blood meal. Once inside the tick, those antibodies bind to OspA and interfere with the bacterium’s ability to migrate out of the tick and into the human bloodstream, a process the companies say blocks transmission before infection can take hold. This transmission-blocking approach is what distinguishes the Pfizer Valneva Lyme disease vaccine from conventional prophylactic shots that work only after a pathogen has already entered the body.

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PF-07307405 covers six of the most prevalent OspA serotypes found in Borrelia burgdorferi sensu lato species circulating across North America and Europe. No Lyme disease vaccine is currently approved for human use anywhere in the world, and this candidate is described as the furthest along the clinical development timeline among Lyme vaccine programs, having completed two pivotal Phase 3 studies. The VALOR trial itself was structured as a multicenter, placebo-controlled, randomized, observer-blinded study, with participants split 1:1 between vaccine and saline placebo groups.

Pfizer and Valneva have worked together on the program since April 2020, when the two companies signed a collaboration and license agreement covering co-development of what was then known as VLA15. Under that arrangement, Pfizer holds exclusive rights to manufacture and commercialize the vaccine candidate should it clear regulatory review, while Valneva continues to contribute its specialty vaccine development expertise. The companies later updated the terms of their partnership through an equity subscription agreement signed in June 2022, a step that helped fund continued clinical development of the Pfizer Valneva Lyme disease vaccine through its Phase 3 program.

PF-07307405 VALOR Phase 3 Trial Snapshot

Pfizer Valneva Lyme Disease Vaccine Program Addresses a Growing Public Health Burden

Lyme disease is transmitted through the bite of infected Ixodes ticks and is recognized as the most common vector-borne illness across the Northern Hemisphere. In the United States, the Centers for Disease Control and Prevention estimates roughly 476,000 people are diagnosed and treated annually, while European countries with active surveillance systems report about 132,000 cases each year. Early symptoms, including an expanding rash known as erythema migrans, fatigue, fever, headache, and joint pain, are frequently mild enough to be dismissed or mistaken for other conditions. These figures illustrate why regulators and public health groups have watched the Pfizer Valneva Lyme disease vaccine program closely as case counts continue to climb across both continents.

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Left untreated, the infection can disseminate and produce more serious chronic effects, including arthritis, carditis affecting the heart, and neurological complications. Public health officials have pointed to an expanding geographic footprint for tick-borne disease as a driver of rising medical need, a trend the companies cited directly in their announcement. Without an approved vaccine on the market anywhere, prevention today relies primarily on protective clothing, repellents, and prompt tick removal, none of which fully close the risk gap for people who spend extended time outdoors.

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