“Lyme” colloquially covers half a dozen to a dozen different bacterial infections.
Just like with syphillis, there is a cheap and simple cure that is more effective than any known vaccine. If it's caught in time. Prevention is even cheaper.
The standard treatment for Lyme also just happens to be the standard treatment for many of the other tick-borne diseases, so you're still better-off taking a course of doxycycline after a tick byte than getting a vaccination against Lyme.
There are also common coinfections which are grouped under the same name, despite being unique.