Abstract
Coronaviruses (CoV) including SARS-CoV and MERS-CoV were responsible for two major pneumonia outbreaks—Severe Acute Respiratory Syndrome (SARS, outbreak in 2003) and Middle East Respiratory Syndrome (MERS, outbreak in 2012) (WHO, 2003; Wu et al., 2020). In humans, CoV infections including CoV-229E, -NL63, -OC43, and -HKU1 (Figure 1A) are seasonal and cause mild upper and lower respiratory tract disease with clinical presentations similar to the flu (Koetz et al., 2006; Gaunt et al., 2010). In December 2019, a novel CoV, now officially named SARS-CoV-2 emerged in Wuhan, China. SARS-CoV-2, a beta-coronavirus (Figure 1A), causes coronavirus disease 2019, simply called COVID-19 (Chan et al., 2020; Zhu et al., 2020). The pathogenesis and clinical outcome of SARS-CoV-2 infection is similar to SARS with fever, cough, and shortness of breath being the most commonly reported symptoms (Mcarthur et al., 2020). SARS-CoV-2 is now pandemic and has infected more than 12 million people and caused more than half a million deaths globally.