As declared by the World Health Organization (WHO), presently the whole world is facing a pandemic and a global crisis caused by a novel virus that was discovered to be the cause of a large and rapidly spreading outbreak of respiratory disease, including potentially fatal pneumonia, in Wuhan, China (starting January 9, 2020). The virus was provisionally designated 2019-nCoV and later given the official name SARS-CoV-2. The disease caused by the virus was officially named Coronavirus Disease 2019 (Covid-19) by WHO.
The SARS-CoV-2 is an enveloped, positive sense, single-stranded RNA virus. Coronaviruses are so named because of their characteristic solar Corona (crown-like) appearance when observed under an electron microscope. This appearance is produced by the peplomers of the surface (or spike; designated S) glycoprotein radiating from the virus lipid envelope.1 The SARS-CoV virion is spherical, with an average diameter of 78 nm (Figure 1).