Incorrect injection time

Puppies mainly rely on maternal antibodies acquired in breast milk to resist viral invasion. Dogs weaned early may have been infected with the virus before their first immunization. If the level of maternal antibodies is too high, it will neutralize the effect of the vaccine and cause immunization. cannot be successful, so the time of first immunization is very important.

Insufficient antibodies

Immunization is to allow the body to produce antibodies to resist viral invasion. Only when the serum antibody titer is greater than 10 international units per milliliter can infectious diseases be prevented. 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.

The virus or bacterial strain has mutated

If the virus or bacterial strain mutates, immunity will also fail. For example, canine parvovirus has undergone several genetic drifts, and a vaccine made with the original strain will not be protective.

Vaccine quality issues

At present, virus vaccines commonly used in China are mainly divided into two categories: attenuated vaccines and inactivated vaccines. If attenuated vaccines are successfully vaccinated, they can produce strong and long-lasting immune effects. However, due to problems such as impure virus strains, stability problems are prone to occur; inactivated vaccines are prone to stability problems; Live vaccines are relatively safe, but less effective and may require multiple injections to produce sufficient antibodies.

Vaccine transportation and storage issues

During the transportation and storage process of the vaccine, the low temperature cannot be guaranteed; after the vaccine is taken out, it is exposed to direct sunlight before immunization or it is taken out for too long, resulting in reduced vaccine activity. Various problems can cause immune failure.

Improper use of vaccines

The vaccine is not released using a special diluent according to the instructions for use, or is not used up within the specified time after dilution, resulting in a greatly reduced stability of the vaccine;

During the process of vaccine dilution or vaccination, too much disinfectant remains on the syringe, or the disinfectant comes into direct contact with the vaccine, causing the vaccine to become ineffective or less effective;

Vaccine injection personnel are not professionally trained, are not skilled in injection operations, miss injections resulting in inaccurate immune doses, and do not inoculate according to the prescribed vaccine methods, etc., can all cause vaccination failure.

Immunity target is in poor condition

Young pets may experience stress caused by transportation, bathing, environmental changes, etc., resulting in reduced immunity, malnutrition, failure to undergo internal and external deworming procedures, already infected with viruses or in the incubation period, early injection of serum by unscrupulous merchants, etc.Cause immune failure.