Viral life cycle
In order for the virus to make copies and infect, it must enter cells of the host animal and use those cells' materials. In order to enter the cells, proteins found on the surface of the virus interact with proteins of the cell. Attachment, or adsorption, occurs between the viral part and the host cell membrane. A hole forms in the cell membrane, then the virus particle or its genetic contents are released into the host cell, where viral reproduction may start.