Pfizer and Valneva Announce Clinical Trial of New Lyme Disease Vaccine

A person poses with a syringe in front of the Pfizer Inc. logo on Dec. 11, 2021. Dado Ruvic/Reuters

Pfizer Inc. and French biotech company Valneva SE are launching a phase 3 clinical study to test an experimental vaccine against Lyme disease, the companies announced on Aug. 8.

Lyme disease is the most common vector-borne disease in the United States and is caused by the Borrelia burgdorferi bacteria. It is transmitted to humans through the bite of infected black-legged ticks, also called deer ticks.

If the trial proves to be successful, Pfizer and Valneva’s experimental vaccine would be the only clinical way to prevent the disease, after the previous vaccine for humans, LYMErix, was discontinued in 2002 due to “insufficient consumer demand,” according to the Centers for Disease Control and Prevention (CDC).

According to a press release, the randomized placebo-controlled trial will include about 6,000 volunteers aged 5 years and older, and will be conducted in up to 50 locations where Lyme disease is highly endemic, including Finland, Germany, the Netherlands, Poland, Sweden, and the United States.

Data from the CDC shows that a total of 34,945 confirmed and probable cases of Lyme disease were reported to state and local health departments by health care providers and laboratories in the United States in 2019.

However, recent estimates using other data collection methods suggest that approximately 476,000 people across the United States may get Lyme disease each year.

Infection Rates Increasing

The European Centre for Disease Control and Prevention says there are several possible causes of the increased incidence of Lyme disease infections, including changing land use patterns, increased density of the deer and rodent population, warmer average temperatures, and habitat encroachment by humans.

The nonprofit organization FAIR Health also analyzed health insurance claims in the United States and found that Lyme disease has drastically increased over the past 15 years, with the illness more than tripling in rural areas (pdf).

Participants in the clinical trial for the new vaccine will receive either three doses of the vaccine, known as VLA15, or three saline placebo shots as a primary vaccination series between August 2022 and the spring 2023 tick season.

After one year, they'll get a single booster dose or another saline placebo.

According to Pfizer, VLA15 “uses an established mechanism of action for a Lyme disease vaccine that targets the outer surface protein A (OspA) of Borrelia burgdorferi” and blocks it, which then “inhibits the bacterium’s ability to leave the tick and infect humans.”

The vaccine is designed to protect people against North American and European strains of the Lyme disease bacteria.

“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, senior vice president and head of vaccine research and 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 [United States] and Europe on this important trial.”

Studies Showing ‘Strong Immunogenicity’

Pfizer and Valneva said that phase 2 studies of the vaccine “continue to demonstrate strong immunogenicity in adults as well as in children, with acceptable safety and tolerability profiles in both study populations.”

If the phase 3 clinical trial proves to be successful, Pfizer may submit a licensing application to the U.S. Food and Drug Administration and a marketing authorization application to the European Medicines Agency in 2025.

Pfizer has agreed to make a $25 million milestone payment to Valneva once the trial begins. The companies began collaborating to develop the vaccine in April 2020.

The majority of cases of Lyme disease can be treated successfully with a few weeks of antibiotics. However, carriers typically experience headaches, fatigue, muscle and joint pains, and a skin rash called erythema migrans. If untreated, it can spread to the nervous system and heart.

Between 1985 and 2019, eleven cases of fatal Lyme carditis were reported worldwide, according to the CDC.