The Virus
SARS-CoV-2 is classified in the Coronaviridae family andbetacoronavirus genus and is the seventh coronavirus known to
infect humans.1 Whereas four coronaviruses, HKU1,
NL63, OC43 and 229E, are associated with mild symptoms akin to the
common cold, SARS-CoV, MERS-CoV, and SARS-CoV-2 have each had recent
outbreaks associated with a more severe disease.23This positive-sense single-stranded RNA virus has a helical capsid
formed by nucleocapsid (N) proteins as well as an enveloped coated with
trimeric spike (S) proteins.1 SARS-CoV-2 infection
begins with viral entry through binding of the SARS-Co-V-2’s S protein
to the angiotensin-converting enzyme 2 (ACE2).24,25TMPRSS2, a transmembrane serine protease, assists in viral entry though
cleavage of the S protein allowing for fusion of the viral membrane with
the host cell membrane. Once intracellular, replication occurs via
RNA-dependent RNA polymerase.