There are four types of vaccines for the prevention of distemper: Serum, Killed Vaccine, Modified Live Vaccine (MLV), and Measles Vaccine.

Serum

Not actually a vaccine, this is a portion of the blood taken from dogs with immunity to distemper. It does not stimulate an immune response and its longevity after injection is relatively short, about a few days. It is a rapid source of antibodies and the advantage is immediate protection. The disadvantage is its short duration and interference with vaccine. It is not usually used in a vaccination program but rather in situations such as pet shops, pounds, etc., where immediate protection is necessary.

Killed Vaccine

This is produced by growing the distemper virus in the laboratory and then destroying it carefully. The end result is a virus particle which will not reproduce or cause disease, but still acts as an antigen and stimulates immunity (antibody production). The major disadvantage is that a fixed amount of virus particles is injected into the dog, which limits the intensity of the antibody response.

Modified Live Vaccine (MLV)

The process for producing this type of vaccine involves growing the virus in the laboratory under conditions that render it harmless, but do not kill it.  When this vaccine is injected, it has the ability to multiply in the body, but yet it will not cause disease. This provides a vast source of antigen and an abundance of antibody.

The duration and height of protection with this type of vaccine is excellent.  It is presently the vaccine of choice for permanent distemper protection. Canine hepatitis and leptospirosis are often combined with MLV distemper vaccines. Care must be taken in the production and handling of this vaccine.

Measles Vaccine

The viruses which cause canine distemper, rinderpest of cattle, and human measles are all similar antigens. The measles virus when injected into the dog will stimulate antibody product which will protect the dog from distemper. The advantage of this drug is that distemper antibodies given to a young puppy through the female’s milk will not attack measles virus, whereas they will attack distemper vaccines.

The result is that very young pups (3 to 4 weeks old) can be vaccinated and develop some permanent immunity. There  is still controversy among many authorities as to the value of the measles vaccine in a vaccination program.