Might double check the age of the dog with Red Rocks to be sure you're within an appropriate timeline. Also, your dog is probably still going through a few rounds of other vaccines then as well, so your vet will likely need to make sure there are no contraindications.
I have used the vaccine for 6 years now and I think that we've seen only one side effect on about 10 dogs and that was a large lump that developed and receded over the period of a couple of weeks. I think that this is a common side-effect of the vaccine.
Do you see many snakes where you are at? I usually give my dogs their vaccine 4-5 weeks before we head to Montana, as that is the place that we are most likely to encounter rattlesnakes.
I'll let others chime in to correct me, but it seems like 6 months is early for snake avoidance. It is my understanding that they do that with an e-collar and I'd be concerned that if you don't have your e-collar conditioning completed by 6 months, that you might get yourself into a big problem later trying to correct behavior with the collar. Once again, I've never had a dog avoidance trained, so there's a high likelihood I am incorrect here, but I'd most certainly consult a professional who works with bird dogs and avoidance.