Major trial of first potential Lyme vaccine in 20 years begins

Major trial of first potential Lyme vaccine in 20 years begins

Researchers are seeking thousands of volunteers in the United States and Europe to take part in a trial of the first potential Lyme disease vaccine in 20 years, hoping to better fight the tick-borne threat.

Lyme disease is a growing problem, with increasing cases and warming weather helping ticks expand their habitat. Although a dog vaccine has long been available, the only Lyme vaccine for humans was pulled from the US market in 2002 due to lack of demand, causing the people relied on bug spray and physically checked for ticks.

Pfizer and French biotech firm Valneva aim to avoid previous pitfalls in developing a new vaccine to protect both adults and children up to five years of age from the most common strains of Lyme on both continents.

“I think there was no such recognition of the severity of Lyme disease” and how many people it affects, Pfizer’s head of vaccines, Annaliesa Anderson, told The Associated Press.

Robert Terwilliger, an avid hunter and hiker, was first in line Friday when the studio opened in central Pennsylvania. He’s seen many friends suffer from Lyme disease, and he’s tired of wondering if his next tick bite will make him sick.

“It’s always a concern, you know? Especially when you’re sitting in a tree hunting and you feel something creep,” said Terwilliger, 60, of Williamsburg, Pennsylvania. “You have to be very, very careful.”

It’s not clear how often Lyme disease affects you. The Centers for Disease Control and Prevention cites insurance records that suggest 476,000 people are treated for Lyme in the US each year. Pfizer’s Anderson put Europe’s annual infections at about 130,000.

Black-legged ticks, also called deer ticks, carry bacteria that cause Lyme. The infection initially causes fatigue, fever and joint pain. Often, but not always, the first sign is a red, round rash.

Early antibiotic treatment is crucial, but it can be difficult for people to know if they have been bitten by ticks, as some are as small as a pin. Untreated Lyme can cause severe arthritis and damage the heart and nervous system. Some people have persistent symptoms even after treatment.

Most vaccines against diseases work after people are exposed to a germ. The Lyme vaccine offers a different strategy by working one step earlier to prevent a tick bite from transmitting the infection, said Dr. Gary Wormser, a Lyme expert at New York Medical College who is not involved in the new research.

How the vaccine works

How does the Lyme vaccine work? It targets an “outer surface protein” of the Lyme bacteria called OspA that is present in the tick’s gut. It is estimated that a tick has to feed on someone for about 36 hours before the bacteria spreads to its victim. This delay in transmission gives time for the antibodies that the tick ingests from the blood of a vaccinated person to attack the germs directly at their source.

In small, early-stage studies, Pfizer and Valneva reported no safety issues and a good immune response from participants. The newest study will test whether the vaccine, called VLA15, actually protects and is safe for people. The companies aim to recruit at least 6,000 people in Lyme-prone areas, including the northeastern United States plus Finland, Germany, the Netherlands, Poland and Sweden.

Volunteers will receive three injections, either the vaccine or a placebo, between now and next spring’s tick season. A year later, they will receive a single booster dose.

“We’re really looking at something that’s a seasonal vaccine,” Anderson said, so people have high antibody levels during the months when ticks are most active.

Volunteers can be as young as five years old and should be at high risk because they spend a lot of time in tick-infested areas, such as hikers, campers and hunters, said Dr. Alan Kivitz, who runs one of the sites of Altoona Center study. Clinical research in Duncansville, Pennsylvania.

In his own practice, “not a single day goes by that someone has a concern about Lyme disease, could possibly have Lyme disease,” Kivitz said.

This new candidate is different from an earlier Lyme vaccine that GlaxoSmithKline pulled from the market in 2002 amid controversy and poor sales. About 75 percent effective, that old Lyme shot got lukewarm support from vaccine experts, wasn’t tested in children and drew unsubstantiated reports of joint-related side effects.

While the new Pfizer-Valneva vaccine also targets the OspA protein, it is designed slightly differently than its predecessor and also targets six strains of Lyme in the US and Europe instead of just one.

The Pfizer study will span two seasons to get answers, but it’s not the only research into new ways to prevent Lyme. Scientists at the University of Massachusetts are also working on a vaccine alternative, made from pre-made Lyme-fighting antibodies.

And Yale University researchers are in the early stages of designing a vaccine that recognizes a tick’s saliva, which in animal tests caused a skin reaction that made it harder for ticks to hold on and feed themselves

Because different tick species carry many different Lyme diseases, ultimately, “we’re all hoping for a vaccine for tick bite prevention,” said New York Medical College’s Wormser.

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