Causes of dog vaccine failure:

1. Insufficient antibodies lead to vaccine failure. Generally speaking, infectious diseases can only be prevented when the serum antibody titer is greater than 10 international units per milliliter. About 30% of dogs develop antibodies one month after the vaccine is injected, and the antibodies reach the highest level one month after the full course of injection is completed. Therefore, if the antibody is not produced or the titer is relatively low before all injections are completed, there is still the possibility of contracting the disease. During this time, dogs must still receive other close precautions.

2. Poor health can lead to vaccine failure. Dogs that are sick cannot be vaccinated. For example, if the parasites are not removed and they have high fever, vaccination will cause immune disorders.

3. The vaccine has become ineffective due to virus infection. Dog vaccines are usually given before a comprehensive physical examination. Although the indicators are normal, the disease may still be in the incubation period and cannot be detected. The antibodies produced by the vaccine are only effective against viruses in the blood and not against viruses that enter cells. Therefore, if the vaccine is already infected with the virus before injection, the injection will not be effective.

4. The mutation of the virus causes the vaccine to become ineffective. Even if the vaccine produces high titers of antibodies, a small number of dogs may still become sick. This is because viruses can mutate, and existing vaccines target normal viruses. If the surface antigen of the virus mutates, and the vaccinated dog is unfortunately infected with this mutated virus, it is still possible to get sick.

5. Improper vaccine injection leads to vaccine failure. Many doctors will inject dogs into the buttocks, but vaccines should not be injected into the buttocks. Because there is a lot of fat tissue in the buttocks and few immune active cells, the antibody titers produced after injection are low and the antibodies decline quickly.

6. Improper timing of vaccine injection leads to vaccine failure. Most of the time it's too early. When antibodies are injected multiple times, some of the antigens are eliminated. Of course, the function that can be produced will be greatly reduced, or the annual vaccinations are not followed according to the doctor's instructions, and of course there is the possibility of infection, since the effect of the vaccine only lasts for one year.