Researchers start testing Lyme vaccine

DUNCANSVILLE, Pa. — Researchers are seeking thousands of volunteers in the U.S. and Europe to test the first potential vaccine against Lyme disease in 20 years — in hopes of better fighting the tick-borne threat.

Lyme is a growing problem, with cases rising and warming weather helping ticks expand their habitat. While a vaccine for dogs has long been available, the only Lyme vaccine for humans was pulled off the U.S. market in 2002 from lack of demand.

Now Pfizer and French biotech Valneva are aiming to avoid previous pitfalls in developing a new vaccine to protect both adults and kids as young as 5 from the most common Lyme strains on two continents.

“There wasn’t such a recognition, I think, of the severity of Lyme disease” and how many people it affects the last time around, Pfizer vaccine chief Annaliesa Anderson said.

Robert Terwilliger, an avid hunter and hiker, was first in line Friday when the study opened in central Pennsylvania. He’s seen lots of friends get Lyme 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 sitting in a tree stand hunting and you feel something crawling on you,” said Terwilliger, 60, of Williamsburg, Pennsylvania. “You’ve got to be very, very cautious.”

Exactly how often Lyme disease strikes isn’t clear. The Centers for Disease Control and Prevention cites insurance records suggesting 476,000 people are treated for Lyme in the U.S. each year. Pfizer’s Anderson put Europe’s yearly infections at about 130,000.

The infection initially causes fatigue, fever and joint pain. Often — but not always — the first sign is a red, round bull’s-eye rash.

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