The final stages of the viral replication cycle are the assembly and exit of new viral particles from the cell. For non-enveloped viruses, release can be achieved through the lysis of cellular membranes. Enveloped viruses need to first be surrounded by a lipid bilayer prior to their extracellular release, typically by exocytosis or budding . Some viruses, such as IAV, use the plasma membrane for envelopment . Other viruses, including the CoVs, subvert ER membrane components for the formation of their own membranes .