Lyme disease: Researchers experiment with a vaccine to reduce the danger of ticks

They are the first vectors of diseases in animals, and the second in humans. Ticks have been the subject of a vaccine experiment to reduce their infection by the bacterium that causes Lyme disease, the National Research Institute for Agriculture, Food and the Environment (Inrae) announced in a press release published on Monday.

Since a vaccine against Lyme disease has not yet been found, “despite extensive research”, researchers from Inrae, the National Agency for Food, Environmental and Occupational Health Safety (Anses) and the Alfort (Val-de-Marne) veterinary school were more interested in ticks than in their victims.

Disrupt the tick microbiota

To do this, they tested a vaccine that alters the tick’s microbiota, where the tick lives. borreliathe bacterium responsible for Lyme disease, in mice, with a harmless bacterium for the experiment.

“Once in the body, this harmless bacterium causes the mouse to produce antibodies. If the mouse is then bitten by a tick, these antibodies interact with the microbiota of the tick and modify it”, explains Inrae, before continuing: “analysis of ticks after the bite shows that they have much less Borrelia than those that have bitten unvaccinated animals.

If this vaccine does not protect the mouse from Lyme disease, it “protects the tick against Borrelia colonization.” This is enough to push researchers to “consider developing an innovative vaccination strategy aimed at altering the microbiota” of ticks.

Between 0 and 20% of infected ticks

Since January 2017, the research institute has recorded more than 72,000 tick bites in France. But not all of these lead to the transmission of Lyme disease. Between 0 and 20% of ticks are infected by the disease depending on the region and season.

To avoid any bite, it is advisable to wear long clothes and stay on the paths avoiding scrub, ferns and tall grass. It is also possible to spray repellents on clothing. Finally, when returning from an outing in nature, it is recommended to inspect the skin to check that it does not have ticks.