Vaccinia virus is the prototypical member of the poxvirus family; it contains double-stranded DNA and replicates in the cytoplasm of infected cells. Intracellular mature virions (IMV) are formed at the intermediate compartment after viral late gene expression. IMV are converted to particles of intracellular enveloped viruses (IEV) when they are enveloped with membrane structures derived from Golgi cisternae. IEV are transported to the cell periphery by interactions with microtubules. IEV fuse with the plasma membrane and remain cell-associated virions or are released from the cells as extracellular enveloped viruses.