First volunteers to receive experimental Lyme disease vaccine in large clinical trial

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A large-scale trial of a much-needed vaccine has just begun.On the weekend, the first batch of volunteers sign up Trial testing candidate Lyme disease vaccine by Pfizer and Valneva.Researchers hope Multiple doses will protect children and adults from six Bacterial strains that cause Lyme disease in the United States and Europe.

The candidate codename is VLA15. Usually, vaccines train the immune system to recognize bacteria, or a significant part of it, so we The real thing is better repelled if it gets into our bodies. However, due to a quirk in the way we capture Lyme virus from ticks, the strategy used by VLA15 has been tweaked a bit. Lyme bacteria (Borrelia) lives in the tick’s gut and is usually only transmitted to humans a day or more after the female tick starts feeding on us. The vaccine is supposed to teach our bodies to find a protein on the surface of the bacteria that causes Lyme disease, called OspA. The hope is that ticks will pick up anti-OspA antibodies from our blood, allowing them to reach the tick’s gut and stop transmission before it spreads.

The new study is the third phase random, double-blind, Placebo-Controlled trial expected to enroll approximately 6,000 volunteers over age 5 People living in areas of the United States and Europe where Lyme disease is endemic (according to trials Pre-registered designs, potentially recruiting up to 18,000 participants). Test subjects will be given three doses of VLA15 or a placebo before the next tick season in the spring, followed by a booster injection a year later. this is possible, Although not yet established, People need boosters to maintain strong immunity to Lyme disease over time.

Annaliesa Anderson, senior vice president and head of vaccine development at Pfizer, said in a statement statement“We hope the data generated from the Phase 3 study will further support the positive evidence for VLA15 to date, and we look forward to collaborating with institutions in the US and Europe on this important trial.”

Even if VLA15 does work as expected and is eventually approved, it won’t be the first vaccine of its kind to reach the public. There is a vaccine for dogs, and in 1998 the OspA-based vaccine LYMERix was approved by the US Food and Drug Administration for use in the US population.but low consumer demand That led its manufacturer to pull the vaccine off the shelves by 2002. LYMERix’s unpopularity may reflect a lack of awareness of Lyme disease as a serious health problem at the time, and that it was not tested and approved for use in children younger than 15. But its lack raised concerns that the vaccine could cause serious, lingering complications in some people, especially the chronic arthritis symptoms that sometimes accompany Lyme disease, a concern that was also shaped by the era. intensified by the anti-vaccination movement.

Then and later studies found no good evidence These speculative risks do exist.Next-generation OspA vaccines, including VLA15, have been further modification To avoid triggering an immune response that could even theoretically lead to such complications. In earlier studies, VLA15 appeared to respond strongly to OspA in volunteers, and no serious safety risks were identified. Unlike LYMERix, VLA15 is also designed to confer immunity against multiple strains of Lyme disease commonly found in the United States and Europe.

Pfizer and Valneva’s vaccine candidates aren’t the only potential anti-Lyme weapons currently in development. Elsewhere, researchers are working with lab-made Lyme antibodies, and the expected strategy is for people to take the antibodies once a year before tick season begins.Scientists at Yale University are studying Tick ​​bite vaccineone that trains the immune system to react quickly to bites, preventing the tick from finishing a meal and spreading Lyme disease as well as other tick-borne infections.

TonThese tools are Very necessary.Nearly half a million Americans are estimated to be infected with Lyme disease each year, and the ticks that spread Lyme disease in the U.S. and Europe are expanding their range and remaining active Into the year long, further endangering more people.

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