animal study offers hope for Lyme disease vaccine | Health Info

By Robert Preidt, Health Day reporter

TUESDAY, Nov 23, 2021 (HealthDay News) – An investigational vaccine against Lyme disease shows promise in animal studies and may help protect against other tick-borne diseases as well, researchers say.

The vaccine – which is based on the same mRNA technology used by some COVID-19 vaccines – protected guinea pigs from infection with Borrelia burgdorferi, the bacteria that causes Lyme disease.

The vaccine does not trigger an attack on the immune system B. burgdorferi. Instead, it causes the skin to respond quickly to certain proteins in tick saliva, reducing the time a tick has to infect the host, the Yale University team explained.

“The vaccine improves the ability to recognize a tick bite, partially turning a tick bite into a mosquito bite,” said lead author Dr Erol Fikrig, professor of medicine and epidemiology at Yale, New York. Haven, Conn.

“When you smell a mosquito bite, you crush it,” he explained. “With the vaccine, there is some redness and probably itching, so you can recognize that you have been bitten and can remove the tick quickly, before it has the ability to transmit. B. burgdorferi. “

Compared to unvaccinated guinea pigs, those that were vaccinated quickly developed redness at the tick bite site. As long as the ticks were removed when the redness appeared, none of the vaccinated guinea pigs were infected. According to the results, about half of the unvaccinated guinea pigs became infected after the ticks were removed.

When a single infected tick was attached to vaccinated guinea pigs and not removed, none were infected, compared to 60% of unvaccinated guinea pigs. But if three ticks remained attached to vaccinated guinea pigs, their protection was not as strong, according to the report published on November 17 in the newspaper. Science Translational Medicine.

The researchers also found that ticks attached to vaccinated guinea pigs were unable to feed aggressively and dislodged faster than those from unvaccinated guinea pigs.

At least 40,000 cases of Lyme disease are reported each year in the United States, but the actual number of infections could be 10 times higher, the researchers noted. Other tick-borne diseases have also spread to many parts of the United States, they added.

“There are several tick-borne diseases, and this approach potentially offers broader protection than a vaccine that targets a specific pathogen,” Fikrig said in an academic press release.

“It could also be used in conjunction with more traditional pathogen-based vaccines to increase their effectiveness,” he added.

More research is needed to find out how proteins in saliva can prevent infection, Fikrig said, and human clinical trials would be needed to assess the vaccine’s effectiveness in humans.

The American Academy of Family Physicians has more on Lyme disease.

SOURCE: Yale University, press release, November 17, 2021

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