Coronaviruses are RNA viruses and have large genomes structures and due to this they can have high error in replication as compared to host genomes. It is also known that various CoVs can do effective recombination of their genomes after infecting host cells . This recombination can be a factor for their evolution to novel types which may have new animals as their intermediate hosts. These factors give the CoVs high adaptive ability and the capability to jump across species and have a relatively large host range.