There is a large-scale trial for a vaccine. The first people to enroll in the trial were from Pfizer and Valneva. Researchers hope that the multi-dose shot will protect kids and adults against six strains of the bacterium that cause Lyme in both the US and Europe.
VLA15 is the candidate's code. Vaccines are usually used to train the immune system to recognize a germ in order to fight it off. Thanks to a quirk, the strategy used with VLA15 is a bit different. After a female tick has started feeding on us, the lymebacteria live inside the gut of the ticks and can only be transmitted to humans a day or more. The vaccine is supposed to help us spot the OspA on the surface of the bacterium. The hope is that the anti-OspA antibodies in our blood will be enough to stop the transmission of the disease.
The new study is a phase III randomized, double-blinded, placebo controlled trial that is expected to enroll around 6,000 volunteers over age 5 who live in areas of the U.S. Before the next tick season starts in the spring, test subjects will be given three doses of VLA15 or a placebo, followed by a booster shot. It is possible that people will need boosters to maintain their immunity against the disease.
According to Annaliesa Anderson, senior vice president and head of vaccine research and development at Pfizer, providing a new option for people to help protect themselves from the disease is more important than ever. We hope that the data from the Phase 3 study will support the positive evidence for VLA15, and we are looking forward to collaborating with the research sites across the U.S. and Europe on this important trial.
It wouldn't be the first vaccine of its kind to reach the public if VLA15 works as intended. The OspA-based vaccine LYmerix was approved for use in the US by the FDA in 1998. The vaccine was pulled off the shelves in 2002. It wasn't tested or approved for children under the age of 15 because of the unpopularity of LYmerix. Its lack of public buy-in was aided by fears that the vaccine could cause long-term problems in some people, particularly the sort of chronic arthritis symptoms seen in people who have been exposed to the vaccine.
There was no evidence that these risks existed. The new generation of OspA vaccines, VLA15 included, have been further modified to avoid provoking the kind of immune response that could potentially cause such problems. VLA15 appears to have produced a strong response to OspA in volunteers with no serious safety risks. VLA15 has been designed to give immunity to multiple strains of the disease.
The vaccine candidate from Pfizer and Valneva isn't the only one in the works. The goal is for people to take the antibodies once a year before the beginning of the tick season. Scientists at Yale are working on a vaccine that would train the immune system to be allergic to a tick, which would prevent it from spreading diseases like tickborne infections.
The tools are necessary. More people are at risk of contracting the disease because the ticks that spread it in the US and Europe are staying active longer.
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