Detailed Explanation of the Patterns of Change in Porcine Circovirus Type 2 Antibodies

Porcine circovirus antibodies show a certain stage-based pattern, with two peaks. One occurs at 1 to 2 weeks of age and consists of maternal antibodies acquired from the mother; the other occurs at 8 to 10 weeks of age and is caused by circovirus infection. Then, in the older pig stage, antibody levels drop to undetectable, which also indicates that infection with the virus at this stage is relatively mild. Porcine circovirus infection is very harmful to pigs. The period when the health level of the herd is relatively low coincides in time with porcine circovirus infection, which provides a theoretical basis for us regarding immune failure, severe secondary infections, the increase in respiratory problems in pigs, and other issues, and also provides new ideas for our prevention and control of the disease.