1. Introduction
A new coronavirus pandemic broke out from Wuhan, China in December 2019 and is still spreading across the globe. The viral causative agent of this infectious calamity was named SARS-CoV2, and the resulting disease is known as coronavirus disease 2019 (COVID-19) [1]. On February 11, 2020, the World Health Organization (WHO) officially declared COVID-19 as a global pandemic [2]. The SARS-CoV2 is the seventh member of the zoonotic family Coronaviridae , genus Betacoronavirus and shows striking resemblance to the other previously identified members, SARS-CoV and middle east respiratory syndrome coronavirus (MERS-CoV), of this family [3]. All three viruses originate from bats and after spending parts of their life cycle in the intermediate hosts (camels for MERS-CoV, civets for SARS-CoV and likely scaly anteaters for SARS-CoV2) are transmitted to humans and cause lethal diseases [4]. The coronaviruses are generally spherical crown-like structures under electron microscopy with an approximate diameter of 125 nm [5]. The whole body consist of a single-stranded positive-sense RNA genome entrapping by a helical nucleocapsid (N) and a borrowed envelope that embrace momentous membrane (M), envelope (E), and especially spike (S) proteins and coverages the remnants [6]. All coronaviruses exploit the host angiotensin-converting enzyme 2 (ACE2) receptor for cellular entry with the help of their S protein except that the SARS-CoV-2 tendency to the ACE2 has greatly increased and entailed higher infectivity [7].