Vaccines are extremely safe. Myth No. 4. Only a tiny minority of genetically-susceptible dogs will suffer adverse reactions to vaccines. Whilst some dogs will have genetic weaknesses that make vaccines more dangerous to them, there are many other factors which can put your dog at risk. Even if the vet does suspect a link, there is no law to make him report the suspected reaction.
Many vets are too busy to complete the necessary paperwork.
Myth No. 5. I am a vet, and I have only seen one vaccine reaction in 20 years' of practice. Because vaccine components can remain in the system for long periods of time, and because most of these disease take time to show themselves, causal link is rarely established. Monkey kidneys, chick embryos, dog brains and kidney, and cat brains and kidneys are all commonly used as vaccine culture media. If the animal used as a culture medium for vaccines carries a retrovirus and this is undetected and left in the vaccine, the vaccine can permanently alter the genes of the animal or human receiving the vaccine.