Vaccines are the most powerful tool available for veterinarians and physicians alike to prevent infectious diseases. They rank among the most revolutionary discoveries in modern history. Millions of lives, human and animal, have been saved by them, and continue to be saved every day. The vast majority of vaccinations today are extremely safe, effective and cause little if any side effects in the recipient. They work by stimulating the body's immune system to react to a foreign substance without making the animal sick. In addition, the animal's immune system retains a memory of the invader so that if exposed to it again in the future, it will react and eliminate it before sickness can set in.
With all of that said however, vaccines are still considered "medications." It is important with any medication that the smallest effective amount be used to minimize potential adverse reactions. However, no one truly knows exactly how long immunity lasts after vaccinations are given, and it can be different for every vaccine given. Most vaccines available for animal use are licensed for 1-3 years and until recently most veterinarians recommended yearly boosters.
But in the last 5-10 years, more and more evidence has surfaced to show that most vaccines may provide immunity for at least 3 or more years. This has prompted many organizations such as the American Veterinary Medical Association (AVMA), American Animal Hospital Association (AAHA) and the American Association of Feline Practitioners (AAFP) to recommend 3-year vaccination protocols for many "core" vaccines. For dogs, this includes Rabies, Distemper and Parvo viruses. For cats, it also includes Feline Leukemia. Guide Dogs for the Blind also supports and recommends these guidelines for all of our program dogs.