Direct cell-to-cell transmission of respiratory viruses: The fast lanes
Fig 2
Different mechanisms of viral spread that may occur in respiratory cells through fast lanes.
From infected cells, completely assembled viral particles are released independently through membrane budding (a), which likely plays a major role in interhost spread of infection. Alternatively, viral infection can be spread intercellularly through fast lanes. This route of infection does not require complete assembly of viral particles and, hypothetically, spread might occur in the form of partially assembled viral particles (b), nucleocapsids (c), or inclusion bodies (d). These mechanisms might not be exclusive, as membrane budding and direct cell-to-cell spread might occur simultaneously in infected cells.