Interesting. At first I figured the title was misleading — surely they meant an anti-Lyme disease vaccination — but it turns out that, no, they mean exactly that: anti-tick. They're training the immune system to recognize the tick saliva. This means that the immune system would recognize the bite much quicker, attack anything associated with it, and in general activate the body's innate immune system faster, leading to a faster response by the adaptive immune system.

In their trials on hamsters, none of the hamsters with the vaccine got Lyme disease, even though it wasn't a vaccine directly targeting Lyme.