Problems related to infections caused by various types of viruses have attracted the scientific community's attention for many years. In 1931, the world's first coronavirus was described - infectious bronchitis virus-IBV. A separate family of coronaviruses was officially established in 1968 and included, in addition to IBV, two human coronaviruses and the mouse hepatitis virus. It quickly became apparent that IBVs are not homogeneous and come in many varieties. Moreover, similar viruses have been identified in other poultry species, and in recent years it has been found that coronaviruses occur asymptomatically in wild birds.
