Fig. 1.

Structure of SARS-CoV-2 virus and its replication kinetics [15]. The N protein holds the RNA genome, and the S, E and M proteins together form the viral envelope. The spike glycoprotein is responsible for allowing the virus to attach to and fuse with the membrane of a host cell. Specifically, its S1 subunit catalyses attachment and the S2 subunit enables fusion (not shown) [15]. Abbreviations: S, spike; E, envelope; M, membrane; N, nucleocapsid; ACE, angiotensin-converting enzyme; mRNA, messenger ribonucleic acid; APC, antigen-presenting cell; Abs, antibodies.