Like karlin said, it's hard to understand how a vet would want to do a routine booster shot on a dog that has had an anaphylactic reaction. Also, you said he is two years old and it was a reaction to his booster shot, so even the conservative protocols of the veterinary associations say that after the first booster, the following vaccinations should be every three years. That doesn't mean you have to do it every three years, but it should mean that you know that you don't have to decide in the next two weeks as you said you did.
If you have a vet who is insisting you re-vaccinate this dog after just one year, that's a sign that your vet is not someone you would want taking care of your pet's health. For a dog who has had such a severe reaction to a vaccination, based on veterinary documentation, states grant waivers to the mandated ongoing rabies shots. If it were me, Iwould find a good vet who would complete the documentation showing that the dog would be at risk of serious complications if vaccinated again so that you can get a legal waiver and be legally excused from having the vaccination.
You will be told in this event that you have to semi-isolate your dog and avoid areas where dogs and animals frequent, but you need to realize that there are extremely qualified experts in immunology who have been persuaded by the evidence they've seen that immunity from the first shot and first booster, as Wilson has had, confer immunity for many years, this has been demonstrated in challenge situations where dogs have been exposed to the disease 7, 8, 9 years and more after vaccination, and don't become ill. These immunologists are trying fund a large scale study that will demonstrate these results once and for all so that laws can be changed. If your 2 year old dog has already been vaccinated and boostered once, you don't have to worry about him getting theh disease and you can get a legal waiver so that your dog won't be confiscated for not being vaccinated.
Nothing is ever 100% but whatever risk Wilson still has of getting the disease that the one he reacted to protects against, would seem to be theoretically less than the risk of him being hurt or killed by revaccination. When i was a kid i watched my mom have an anaphylactic reaction to penicillin. It was scary, an ambulance came and she had shots of adrenaline to save her life. she wears a pendant that says she must never have penicillin again.
I don't know which vaccinations Wilson received or which one was considered the likely cause of the reaction, but as Sandy said, many vaccinations, including the core vaccinations, confer long term immunity. You don't have an unprotected unvaccinated dog, your dog likely will remain immune for a long time or for life. It's not just Sandy's opinion, it's the firm belief of the leaders in the field of veterinary medicine that because the evidence suggests long term or permanent immunity, waiting 3 years between shots is very reasonable compared to annual revaccination with those vaccines. Some vaccinations need to be done more often, (if at all) but the core ones that you seem to be talking about have long term effects.
read this, or print it and mail it to your vet and anyone else who questions whether your dog is protected:
http://www.britfeld.com/health/canine_vaccine_guidelines.pdf
Check out the links to this one:
http://www.caberfeidh.com/Revax.htm
In your case, i don't think you have a choice. How can you risk vaccinating him, regardless of what uninformed people think?
i don't mean to downplay the persecution of being ostracised and judged by the ignorant, it's a real problem. but Wilson's health would be the highest priority. sorry you have to find yourself in this position.