SARS-CoV-2 infection apparently emerged in China
in December 2019, causing the disease known as
COVID-19,which can cause severe damage to vital organs
(Ackermann et al, 2020). Spillover of SARS-CoV-
2 from bats to humans has been hypothesized
(Ackermann et al, 2020). The virus spike protein is
the main determinant of viral tropism because it is
responsible for binding to the angiotensin converting
enzyme 2 (ACE2) and subsequent entry of SARSCoV-
2 to host cells in humans and several animal species
(Sun et al, 2020). Therefore, it is reasonable to hypothesize
that the spike proteineACE2 receptor
complex may represent evolutionary exploitation to
overcome speciesbarriers to infection, thushighlighting
the zoonotic origin and transmission of the virus
