Scientists are developing a vaccine to help treat Lyme disease.

Humans can get Lyme disease through the transmission of the Borrelia burgdorferi bacterium from the bite of an infected tick.

Called VLA15, the vaccine works by stimulating the immune system to make antibodies that ward off 6 of the most common types of Lyme-causing bacteria in the tick’s gut.

Valneva, the biotech company in France developing the vaccine, is currently in phase II of testing. Writes the Scientific American:

The Food and Drug Administration gave VLA15 fast-track designation in July 2017. Valneva completed initial safety studies in a Phase 2 clinical trial and, according to a company press release , VLA15 “had no associated safety concerns.” The company is now working to determine the dose. Based on current estimates, Lingelbach said Valneva plans to test the vaccine in a clinical trial of at least 15,000 people, and it should be available in four or five years.

There is a second immunity being developed to prevent Lyme disease as well.

Called Lyme pre-exposure prophylaxis (Lyme PrEP), it works by sending a single antibody as a vaccine and is known to have fewer side effects than the VLA15.

The new vaccines build off the original Lyme disease vaccine called LYMErix developed twenty years ago. But production stopped due to fears of the side effects.

Unlike other viruses, Lyme disease is hard to treat since it pervades the body’s tissue in addition to the blood. Joint pain, heart palpitations, muscle weakness, and confusion are some of the symptoms of Lyme disease.

In a worst-case scenario, the bacteria can even dominate the entire central nervous system, producing disastrous effects on the human body.