US, Europe begin testing first possible Lyme disease vaccine in 20 years – National Globalnews.ca

Researchers are recruiting thousands of volunteers across the US and Europe to test the first potential Lyme disease vaccine in 20 years – hoping to better combat the tick-borne threat.

Lyme is a growing problem, with increasing cases and warmer weather helping ticks expand their habitat. While a canine vaccine has long been available, the only human Lyme vaccine was pulled from the US market in 2002 due to lack of demand, leaving people to rely on bug spray and tick controls.

Now, Pfizer and French biotech Valneva aim to avoid previous pitfalls by developing a new vaccine that protects both adults and children as young as 5 against the most common Lyme strains across two continents.

“I think there was no such recognition of the seriousness of Lyme disease” and how many people it affects last time, Pfizer vaccine chief Annaliesa Anderson told The Associated Press.

Robert Terdlinger, an avid hunter and hiker, came first on Friday as the study opened in central Pennsylvania. He has seen many friends get Lyme disease and is tired of wondering if his next tick bite will make him sick.

“It’s always a worry, you know? Especially when you’re hunting in a stand of trees and you feel something crawling on you,” said Terdlinger, 60, of Williamsburg, Pennsylvania. “You have to be very, very careful.”

Exactly how often Lyme disease occurs is not clear. The Centers for Disease Control and Prevention cite insurance records showing that 476,000 people are treated for Lyme in the United States each year. Pfizer’s Anderson put the annual infections in Europe at around 130,000.

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

Early treatment with antibiotics is crucial, but it can be difficult for people to tell if they’ve been bitten by ticks, some of which are as small as a pin. Left untreated, Lyme disease can cause severe arthritis and damage to the heart and nervous system. Some people have persistent symptoms even after treatment.

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Ticked off: Tick numbers are increasing

Most vaccines against other diseases work after people have been exposed to a germ. The Lyme vaccine offers a different strategy — it works one step earlier to prevent transmission of the infection through a tick bite, said Dr. Gary Wormser, a Lyme expert at New York Medical College who is not involved with the new research.

As? It targets an ‘outer surface protein’ of the Lyme bacterium called OspA, which is present in the tick’s gut. It is estimated that a tick needs to feed on someone for around 36 hours before the bacterium spreads to its victim. This delay gives time for the antibodies that the tick picks up from the blood of a vaccinated person to attack the germs directly at the source.

In small, early-stage studies, Pfizer and Valneva reported no safety issues and a good immune response. The latest study will test whether the vaccine, called VLA15, is truly protective and safe. The companies are aiming to hire at least 6,000 people in Lyme-prone areas, including the Northeast US, Finland, Germany, the Netherlands, Poland and Sweden.

You will receive three vaccinations, either the vaccine or a placebo, until next spring’s tick season. A year later, they receive a single booster dose.

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

Volunteers can be as young as 5 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 directs one of the study sites at the Altoona Center for Clinical Research in Duncansville, Pennsylvania.

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

This new candidate differs from a previous Lyme vaccine that GlaxoSmithKline pulled from the market in 2002 amid controversy and poor sales. With an efficacy of about 75%, this old Lyme vaccine received lukewarm endorsement from vaccine experts, has not been tested in children, and led to unfounded reports of joint-related side effects.

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

The Pfizer study will span two tick seasons to get answers — but it’s not the only exploration of new ways to prevent Lyme. University of Massachusetts scientists are working on a vaccine alternative, shots of ready-made Lyme disease-fighting antibodies.

And researchers at Yale University are in the early stages of developing a vaccine that recognizes a tick’s saliva — which in animal studies elicited a skin reaction that made it difficult for ticks to attach and eat.

Because different species of ticks transmit many diseases other than Lyme disease, “ultimately we’re all hoping for a vaccine to prevent tick bites,” Wormser said.