- Pfizer announced that the company has developed a Lyme disease vaccine.
- The vaccine, VLA15, is the only Lyme disease vaccine for humans in clinical development.
- The vaccine is moving to a Phase 3 study.
Pfizer shared big news on Monday: The company has developed a Lyme disease vaccine that’s in late-stage clinical trials. The vaccine, which is called VLA15, is the only Lyme disease vaccine for humans that’s in clinical development.
Lyme disease is the most common vector-borne disease in the U.S. according to the Centers for Disease Control and Prevention (CDC). It’s transmitted to people through the bite of infected black-legged ticks. Lyme disease symptoms can include fever, headache, fatigue, and a skin rash called erythema migrans, which creates a bulls-eye rash. If it’s left untreated, Lyme disease can spread to the joints, heart, and nervous system, the CDC says.
Pfizer’s vaccine is moving into a Phase 3 study and plans to enroll about 6,000 people ages five and up.
“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, Ph.D., senior vice president and head of vaccine research and development at Pfizer, said in a press release. “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 U.S. and Europe on this important trial."
Phase 3 clinical trials are being held in 50 areas across the globe where Lyme disease is common, including the U.S., Finland, Germany, the Netherlands, Poland, and Sweden.
This isn’t the first vaccine for Lyme disease made available to the U.S.: There was a vaccine called LYMErix available in the U.S., but it was discontinued in 2002 due to “insufficient consumer demand,” according to the CDC.
How does the Lyme disease vaccine VLA15 work?
VLA15 is a three-dose vaccine given over five to nine months, followed by a booster dose a year later, according to Pfizer. “Some vaccines take more to stimulate the immune system in a sufficiently secure way so you can get adequate protection,” explains William Schaffner, M.D., infectious disease specialist and professor at the Vanderbilt University School of Medicine.
The vaccine targets the outer surface protein A of Borrelia burgdorferi, the bacteria that cause Lyme disease, which is expressed by the bacteria in ticks. Blocking outer surface protein A keeps the bacteria from leaving the tick and infecting people, Pfizer explains. The vaccine covers the six most common types of outer surface protein A expressed by ticks in North America and Europe.
What have the vaccine’s clinical trial results shown so far?
There’s not a lot of information available about the vaccine data so far. Pfizer says that Phase 2 clinical trials “continue to demonstrate strong immunogenicity in adults as well as in children, with acceptable safety and tolerability profiles in both study populations.”
According to Valneva, which is making the vaccine with Pfizer, Phase 2 clinical trials followed 294 healthy adults who received either two or three doses of the vaccine. While both groups developed good immune responses, antibodies were higher in people who received the three-dose series. Similar results were found for study participants between the ages of five and 17, Valneva says.
Why do we need a Lyme disease vaccine?
Each year, about 30,000 cases of Lyme disease are reported to the CDC, but the organization says this is likely an undercount. CDC estimates show that about 476,000 people in the U.S. may get Lyme disease each year.
“Returning a vaccine for Lyme disease to the U.S. market would be a major advance at controlling this endemic infection,” says infectious disease expert Amesh A. Adalja, M.D., a senior scholar at the Johns Hopkins Center for Health Security. “Lyme disease exacts a significant burden on the population and the healthcare system and a vaccine could substantially lessen that burden.”
William Schaffner, M.D., infectious disease specialist and professor at the Vanderbilt University School of Medicine, calls the news “very exciting.” He adds, “many people wish we had a Lyme disease vaccine.”
“Lyme disease is increasing in the U.S.—and it’s a very troublesome illness with lots of consequences,” Dr. Schaffner says. While Lyme disease is most common in New England and the upper Midwest, Dr. Schaffner points out that cases are spreading out of those areas.
When will the Lyme disease vaccine be available?
It’s unclear at this point. The vaccine still needs to get through Phase 3 clinical trials. If those go well, Pfizer says it plans to submit a license application to the FDA. But the FDA’s timeline can vary and the vaccine would need to also be given the thumbs up from the CDC before it could be used by the general public. Depending on the timing of all of that, the vaccine could be available for use sometime in 2025 or 2026.
Who will be able to get the Lyme disease vaccine?
Research on the Lyme disease vaccine is ongoing and Pfizer says it doesn’t anticipate submitting a license application to the Food and Drug Administration (FDA) until 2025. Still, if and when it’s available, “individuals who live in endemic areas of the U.S. would greatly benefit,” Dr. Adalja says. Dr. Schaffner agrees, adding, “one would anticipate it would be very popular.”
