Michael Stone, a staff veterinarian and clinical assistant professor at Cummings School of Veterinary Medicine, responds
You ask about the benefits of the canine vaccine against Lyme disease. That is a great question. Unfortunately, veterinarians do not have a complete answer when it comes to the vaccine’s effectiveness. Some research suggests that vaccination appears to be fairly good in preventing infection in dogs not previously exposed to the Lyme organism. I word this carefully, though, because your dog already has been exposed, and there’s no known benefit of vaccination after an initial exposure to the Lyme-causing bacteria.
You also ask about the risks of the vaccine. We have a bit more information about that, because veterinarians have been using it for several years. There is a very low incidence of side effects, less than 2 percent. As with most vaccines, reactions might include facial swelling, hives, itchiness, swelling at the vaccination site and, less commonly, collapse.
So what is my best advice? I do not routinely encourage vaccination against Lyme, even though I practice in a region where the disease is endemic. That said, I do not hesitate to administer the vaccine when a pet owner requests it, because I believe it is safe.
However, because I’m not convinced of its effectiveness in preventing Lyme disease, I would emphasize that tick control still remains important. There are other diseases that can be transmitted by tick bites—Lyme vaccine does not prevent those other infections. Tick control for all dogs in tick-infested locations is more important than vaccination. There are both collar and topical products that are safe and effective in deterring ticks.