*1.1. SARS-CoV-2: An Overview*

Coronaviruses (CoVs) belong to the coronaviridae family, which comprises a group of positive-enveloped single-stranded RNA viruses. These viruses have the largest genome among RNA viruses, and morphologically they appear as surrounded by a corona under the electron microscope [6].

Like other coronaviruses, SARS-CoV-2 has four structural proteins, known as: protein S (ear or spinule), E (envelope), M (membrane) and N (nucleocapsid); the N protein contains the RNA genome while the S, E and M proteins together create the viral capsid. Specifically, there are three protein components of the viral envelope. The most important of these is the S-glycoprotein (Spike), a very large transmembrane protein that mediates attachment to the receptor and the fusion of the cell membrane of the host cell with that of the virus. M-glycoprotein is the most abundant constituent of CoVs and shapes the virion envelope. Protein E is a small polypeptide, and due to its small size and limited amount, E was detected much later than other structural proteins [6].
