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, leaving people to rely on bug spray and tick checks.
Now
“There wasn’t such a recognition, I think, of the severity of Lyme disease" and how many people it affects the last time around,
“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
Exactly how often Lyme disease strikes isn't clear. The
Black-legged ticks, also called deer ticks, carry Lyme-causing bacteria. 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.
Most vaccines against other diseases work after people are exposed to a germ. The Lyme vaccine offers a different strategy — working a step earlier to block a tick bite from transmitting the infection, said Dr.
How? It targets an “outer surface protein” of the Lyme bacterium called OspA that’s present in the tick’s gut. It’s estimated a tick must feed on someone for about 36 hours before the bacteria spreads to its victim. That delay gives time for antibodies the tick ingests from a vaccinated person’s blood to attack the germs right at the source.
In small, early-stage studies,
They’ll receive three shots, either the vaccine or a placebo, between now and next spring’s tick season. A year later, they’ll get 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 5 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.
In his own practice, “not a single day goes by that someone either has a concern about Lyme disease, could possibly have Lyme disease,” Kivitz said.
This new candidate is different from a previous Lyme vaccine that
While the new Pfizer-Valneva vaccine also targets the OspA protein, it's engineered somewhat differently than its predecessor and also targets six Lyme strains in the
The
And
Since different tick species carry many diseases other than Lyme, ultimately “we're all hoping for a tick-bite prevention vaccine,” Wormser said.
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