There's no-one to go to if you want an independent check. It's better to risk a vaccine reaction than subject my dog to these deadly killer diseases. Firstly, very few of the classic canine diseases are deadly. Parvovirus is only generally deadly to puppies and, as maternal antibody can be present for as many as 22 weeks, and as maternal antibody cancels out the vaccine, vaccinated puppies are unlikely to be protected from parvovirus. Adult dogs rarely die from parvovirus.
Distemper kills only half of affected dogs.
A dog fed a natural diet, containing 'real' food, is most able to combat any viral challenges. Also, please be aware that there is an alternative to a highly risky vaccine - this is discussed later. Secondly, no-one knows how common these diseases are. No-one records their existence. Vaccines have also been known to cause the diseases they were designed to prevent.