Vaccine makers are one step closer to developing possible new protection against Lyme disease.
Pfizer and Valneva announced in August 2022 plans to begin a Phase 3 clinical trial of a new Lyme disease vaccine candidate, VLA15.
There is no current human vaccine available for Lyme disease, which is the most common vector-borne illness in the U.S. The Pfizer-Valneva vaccine is the only Lyme disease vaccine in development.
If the clinical trial goes well and the U.S. Food and Drug Administration (FDA) authorizes VLA15, it could be available to humans by 2025.
“This is going to be a big game-changer in our fight for the prevention of Lyme disease,” says Dr. Rutul Dalal, MD, specialist, Infectious Diseases, UPMC in North Central Pa.
Here’s what to know about the possible Lyme disease vaccine.
Why Is a Lyme Disease Vaccine Needed?
A vaccine can help prevent Lyme disease cases. According to the Centers for Disease Control and Prevention (CDC), recent estimates say about 476,000 people get Lyme disease annually in the U.S.
Lyme disease can cause both short-term and long-term symptoms. Long-term complications can include neurological, cardiac, and musculoskeletal conditions. In some people, these complications can become disabling.
Although there is a Lyme disease vaccine for dogs, there is no current vaccine for humans. A previous human Lyme disease vaccine went off the market in 2002.
Dr. Dalal says a Lyme disease vaccine could be particularly important in Pennsylvania. The state often has one of the highest numbers of Lyme disease cases in the U.S.
“Pennsylvania, unfortunately, has the dubious distinction of being number 1 in the country to have the highest number of cases,” he says. “And as we speak every year, almost half a million Americans get Lyme disease. And that could be even an understatement because many other patients do not get even diagnosed with Lyme disease.”
How Does the Lyme Disease Vaccine Work?
The potential Lyme disease vaccine targets an outer surface protein of Borrelia burgdorferi, the bacteria that causes Lyme disease.
Lyme disease spreads through the bite of a tick infected with Borrelia burgdorferi. By targeting the protein on the bacterium’s surface, the vaccine can prevent it from spreading to humans.
The vaccine targets six different strains of Lyme disease that are present in the U.S. and Europe.
Is the Lyme Disease Vaccine Safe?
Before the vaccine could reach the third phase of a clinical trial, researchers had to show safety and efficacy in earlier phases. During the second phase, the vaccine proved it could raise an immune response in adults and children. Researchers reported no major safety concerns.
The third phase of the clinical trial will test the vaccine’s safety and efficacy in humans aged 5 and older.
About the Lyme Disease Vaccine Clinical Trial
Pfizer and Valneva are currently seeking participants for the Phase 3 clinical trial.
The trial will include about 6,000 participants ages 5 and older from areas in the U.S. and Europe where Lyme disease is prevalent.
“Potential candidates would be from all over Europe and also from the U.S.,” Dr. Dalal says. “It contains people of all strata, of all ages, of all genders.”
The study will follow trial participants through two tick seasons. They will get three doses of the vaccine or the placebo before the start of the spring 2023 tick season. Then they will receive a booster dose before the start of the spring 2024 tick season.
For more information, visit the study website.
When Will the Lyme Disease Vaccine Be Available?
If the clinical trial is successful, Pfizer could submit a license for authorization to the FDA in 2025. The vaccine will not be available to the general public until then.
Although the vaccine is still a few years away from potentially being available to the public, Dr. Dalal still believes it could be a “game-changer” in the fight against Lyme disease. Other prevention methods can help against Lyme disease, but a vaccine would be significant, he says.
“Hopefully once approved, we will be able to contain this pesky bacterial infection which comes in the spring, summer, and also now into fall and sometimes even into early winter,” Dr. Dalal says.