ABSTRACT
Viruses are obligate intracellular parasites, and utilize the host cell’s organelles and metabolic pathways for their own reproduction. At the most basic level, a virus particle (a virion) consists of a nucleic acid genome packaged within a protein coat. For viral replication to occur the virion must deliver the nucleic acid to the host cell. Viral entry, replication and the measures used by the host to eliminate the virus have been the subject of intense study for many years. More recent is the realization that coexistence with the host requires a virus to deal with the complexities of both the innate and acquired immune system that may be activated from the moment of viral entry.
