There are few sicknesses snakes can get

most common problems are mites and RI, both can usually be avoid by following correctly husbandry procedure. Mites can are like fleas or ticks, they latch on to things but they need a snake host, so simple things like quarantine and washing your hands/change clothes when you go to a reptile show can go a long way. If you know what to look for with RI, it rarely gets to the point where they need to go to a vet.

there are other things like IBD but vets can't even do anything about it.

but as far as vaccination, i don't think they exist for snakes and vet visits aren't needed unless something bad is going on you can't treat yourself. I've herd of some people doing yearly check ups, but most people don't.

Transfer just wash your hands if you have a sick snake so other don't get sick, already told you about mites, wash your hands after visiting other people's collection. but if you or your dog is sick, it won't effect the snake.