There is a lot of questioning now about the amount of routine shots and some veterinarians are starting to think maybe it is not a good idea. I would recommend two books that may help answer your question, both are available at amazon, and reasonably priced :
Dr. Richard Pitcairn: Natural Health For Dogs And Cats
Dr. Martin Goldstein: The Nature Of Animal Healing
If that is your cat in your picture, you have a beautiful cat! I would have a hundred cats if I could.