CAUSES OF VACCINATION FAILURE-HOST FACTORS

1. Maternal antibody interference

Interference by maternal antibody is one of the major causes of vaccination failure in young animals. High levels of maternal antibodies present in puppy’s or kitten’s bloodstream will block the effectiveness of a vaccine. There is period of time in which maternal antibodies are too low to protect the animal from the disease, but too high to allow a vaccine to work. It is the window of susceptibility where despite being vaccinated, the animal still can tract the disease. Before conformation of immunization success, pups or kittens should be isolated from other pups or kittens of unknown immunization status and not advisable to go to places that may have risk of infection.

2. Immunodeficiencies

Without a functional immune system, the vaccinated animal could not respond well to a vaccine challenge. For example, in animal that with certain viral infection and those receiving certain cancer treatments or with very high doses of steroids, the vaccine would not initiate a proper immune response, and would not immunize the animal from the diseases.

3. Stress conditions

Natural cortisols produced during times of prolonged and excessive stress where it may suppress the immune response to vaccination. Example: pregnancy, anesthesia, surgery, excessive transportation, boarding and others.

4. Age

Either too young where the immune system is still immature OR too old where the immune system started to deteriorate, the vaccine may have less or no effect in stimulating imuunity.

5. Concurrent or incubating disease

Pyrexia, hypothermia or incubating disease may decrease the ability of the immune system to adequately respond to vaccination.

6. Malnutrition

Poor nutrition, such as restricted protein and calories, vitamin A deficiencies and vitamin E deficiencies can result in immune system suppression