We’ll never know until we skip a vaccination and expose your dog to the infectious disease. Believe it or not, the vast majority of veterinarians are making the best recommendation for your pet. Veterinarians tend to be high empathy people, and are not in this to make money.
The American Animal Hospital Association has been working for years to develop vaccination guidelines, working with vaccine manufacturers, immunologists, specialists, and general practitioners.
See the following link for more than you probably want to know, then ask your veterinary practice for more information specific to your region, and to your household.