What makes a vaccine a “core vaccine”? The diseases covered by core vaccines all have significant rates of infection, are difficult to treat, and have high risks of permanent health problems and/or death. These diseases are widely distributed, and the vaccines provide good to excellent protection against them. Core vaccines include the three most life-threatening canine diseases: Distemper, Parvovirus, and Rabies. Adenovirus (Canine Hepatitis) is also included in this list, even though canine hepatitis is rarely seen in domestic dogs in the past 20 years. It is often combined with Distemper and Parvovirus to make the DAP (or DHP) vaccine.

Duration of immunity—how long the dog will be immune to the disease after vaccination—is quite high for the core diseases. The minimum duration of immunity for these four viral diseases is for many years, if not for the life of the dog. Challenge studies have indicated a minimum of 3-7 years of immunity from these vaccines, with a minimum of 9 years by serology (testing antibody levels in the blood). This means that only a few properly timed vaccinations can provide life-long immunity to these viral diseases, without requiring excessive yearly “booster” shots. Fortunately, yearly vaccinations for these diseases are no longer recommended by all 27 veterinary universities in the U.S., and most enlightened vets have moved to a three-year revaccination schedule.

What is a “non-core” vaccine? Non-core vaccines are optional vaccines for diseases that are restricted in their geographic distribution (found only in certain climates or parts of the country), are self-limiting or respond readily to various treatments (such as antibiotics), and have a lower rate of mortality. Non-core vaccines cover such diseases like canine parainfluenza virus, canine influenza, Bordatella/Kennel Cough, Leptospirosis, Lyme. These vaccines are typically for bacterial diseases, and are often limited in their effectiveness. Thus, they must be administered yearly to provide maximum coverage, and even then these vaccines do not offer full protection, meaning animals that have been vaccinated are still at some risk for contracting the disease. Vaccines for Leptospirosis and Lyme also have a higher rate of adverse reactions, including life-threatening anaphylaxis. Duration of immunity for non-core diseases is very short, ranging from 6 months to 1 year. While not a bacterial vaccine, the Rattlesnake vaccine is also included as a non-core vaccine, as it demonstrates a short duration of usefulness and a lack of efficacy.

In our next blog, we will specifically discuss the core diseases and their vaccines.