The first stage in viral replication occurs when a virus attaches to the surface of a host cell. The viral nucleic acid (VNA) then enters the cell. The VNA then takes over the cell, altering the metabolism of the cell, meaning it will start to produce proteins and lipid coats for the Virus, and the VNA is replicated using the host cell ribosomes. The replicated VNA is then assembled in the cell with the newly synthesised protein coats. Finally, the new virus molecules leave the cell via lysis, whereby the host cell bursts.