There is an interesting article on veterinary vaccines which you can read in its entirety at the link below.
Are Our Pets Being Overvaccinated, by Melissa Burden, The Press
Main News (Dr. W. Jean Dodds) “But there is really no breed that is not at risk,” she said. The only vaccination needed, she asserts, is the rabies vaccine because it is legally required. Dogs’ and cats’ immune systems mature fully at 6 months old, she explained. If canine distemper, feline distemper and parvovirus vaccines are given after 6 months, a pet has immunity for the rest of its life. (Dr. Robert Rogers) “Dogs and cats no longer need to be vaccinated against distemper, parvo, and feline leukemia every year,” Rogers said. “Once the initial series of puppy or kitten vaccinations and first annual vaccinations are completed, immunity…persists for life. Not only are annual boosters for parvo and distemper unnecessary, they subject the pet to the potential risk of adverse reactions, he added.