The dog vaccine is ineffective or the antibodies are insufficient

Whether the vaccine can prevent diseases after injection depends on whether the vaccine can stimulate the dog to produce antibodies and the amount of antibodies (expressed by titer). It is generally believed that infectious diseases can be prevented only 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.

According to research, dogs can be divided into four groups based on their antibody titers to vaccines:

1. The non-responsive group accounts for about 5% of the number of injections. The main reason why dogs don’t respond to vaccines is mostly genetic factors. The ability of vaccination to produce antibodies is controlled by type II major histocompatibility complex (MHC) and is a dominant inheritance.

2. Low response group. The serum antibody titer produced after vaccination is less than 10 international units per milliliter, accounting for approximately 10% of the total number of injections. This is related to factors such as genetics, age, obesity, immunosuppression, and immune tolerance.

3. Medium reaction group. The titer of serum antibodies produced after vaccine injection is 10 to 100 international units per milliliter, accounting for approximately 65% ​​of the number of injections. 4. High response group. Serum antibody titers greater than 100 international units per milliliter accounted for approximately 20% of the injections. Dogs in the non-responsive and low-responsive groups may still get infectious diseases after vaccination.

Dogs have been infected with the virus before vaccination

Even if the dog is examined before vaccination and all indicators are normal, it may still not be detected because it is in the incubation period of the disease. The antibodies produced by the vaccine are only effective against viruses in the blood and are ineffective against viruses that have already entered cells. Therefore, if you have been infected with the virus before the vaccine is administered, the vaccine will not be effective.

Improper storage of vaccines

Vaccines should not be frozen. Freezing can damage their structure. The storage time at 37 degrees Celsius should not exceed one month, and the storage time at 4 degrees Celsius should not exceed one year. If stored for too long, the immune effect will be reduced. Household refrigerators can be placed in the cold storage compartment.

Improper use

Vaccines should not be injected into the buttocks. There is a lot of fat tissue in the buttocks and few immune active cells. The antibody titer produced after injection is low and the antibody decreases quickly.

Mutation of the virus

Even if the vaccine produces high titers of antibodies, a small number of dogs may still get 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.

Poor health

For example, parasites have not been removed, high fever, etc., resulting inImmune dysregulation.

Wrong injection time, too late, too early

When antibodies are injected multiple times, some of the antigens are eliminated. Of course, the functionality that can be produced is significantly reduced. Or if you don't follow the doctor's instructions for boosting for more than a year, there will be no increase. Of course, there is also the possibility of infection, because the effect of the vaccine can only last for one year.

When individual dogs have imperfect immune systems or are taking certain drugs

Undoubtedly, immunity is the basic guarantee for dog health, and it is also the basic obligation of every dog ​​owner. You should not think that everything will be fine after being vaccinated, nor should you simply not vaccinate your dog just because you still get an infectious disease after being vaccinated. A full set of tests should be carried out after vaccination. If no antibodies are produced, the vaccine should be revaccinated. In order to increase the chance of immune success, some experts believe that supplementing zinc, IL-2 or thymosin may increase antibody titers, so you might as well give it a try.