Table 1.

Comparison of known human coronaviruses.

Genus	Alphacoronavirus		Betacoronavirus
Strain	HCoV-229E	HCoV-NL63	HCoV-OC43	HCoV-HKU1	SARS-CoV	SARS-CoV-2	MERS-CoV
Disease	mild upper respiratory tract infection	mild upper respiratory tract infection	mild upper respiratory tract infection	pneumonia	Severe acute respiratory syndrome (SARS)	Coronavirus Disease 2019 (COVID-19)	Middle East respiratory syndrome (MERS)
Receptor on human cells	APN	ACE2	ASA	ASA	ACE2	ACE2	DPP4
Tissue/organ tropism	Monocytic and granulocytic lineage; synaptic membranes of the central nervous system; intestinal, lung and kidney epithelial cells	Arterial and venous endothelium; arterial smooth muscle; small intestine, respiratory tract epithelium; alveolar monocytes and macrophages	Sub-maxillary mucin	Airway epithelium, alveolar cells	Arterial and venous endothelium; arterial smooth muscle; small intestine, respiratory tract epithelium; alveolar monocytes and macrophages		Respiratory tract epithelium; kidney, small intestine; liver and prostate; activated leukocytes
Natural host/reservoir/	bats	bats	rodents	rodents	bats	bats	bats
Intermediate host	dromedary camels, alpacas	palm civets	cattle	mice	palm civets, raccoon dog	pangolin, bats	dromedary camels
Symptoms	Malaise, headache, nasal discharge, sneezing, sore throat, fever, cough	Cough, Rhinorrhea, tachypnea, fever, hypoxia, croup	Malaise, headache, nasal discharge, sneezing, sore throat, fever, cough	Fever, running nose, cough, dyspnea	Fever, myalgia, headache, malaise, dry cough, dyspnea, respiratory distress, diarrhea	Fever, dry cough, dyspnea, myalgia, headache, diarrhea, fatigue, shortness of breath, sore throat, nausea, vomiting, rhinorrhea, conjunctivitis	Fever, cough, chills, sore throat, myalgia, arthralgia, dyspnea, pneumonia, diarrhea and vomiting, acute renal impairment
Transmission	Respiratory droplets, fomites	Respiratory droplets, fomites	Respiratory droplets, fomites	Respiratory droplets, fomites	Respiratory droplets, fomites, fecal-oral	Respiratory droplets, fomites, fecal-oral	Respiratory droplets, fomites
Transmission by asymptomatic patient	not reported	not reported	not reported	not reported	very rare	often	no
References	(Belouzard et al., 2012, Corman et al., 2015, Corman, Muth, Niemeyer, & Drosten, 2018, Fung and Liu, 2019, Lim et al., 2016, Ye et al., 2020, Chen et al., 2020, Fan et al., 2019, Fung and Liu, 2019, Wang et al., 2006, Xu et al., 2009); (Chen et al., 2020, Fan et al., 2019, Fung and Liu, 2019, Lim et al., 2016, Wang et al., 2006, Xu et al., 2009, Ye et al., 2020)	(Fung & Liu, 2019; Lim et al., 2016; Ye et al., 2020)	(Belouzard et al., 2012; Fung & Liu, 2019; Lim et al., 2016; Ye et al., 2020)	(Dijkman et al., 2013, Fung and Liu, 2019, Hu et al., 2015, Lim et al., 2016, Ye et al., 2020)	(Chen et al., 2020, Fan et al., 2019, Fung and Liu, 2019, Lim et al., 2016, Wang et al., 2006, Xu et al., 2020, Ye et al., 2020)	(Chan et al., 2020, Fung and Liu, 2019, Gu et al., 2020, Hu et al., 2020, Lim et al., 2016, Liu et al., 2020, Lu et al., 2020, Meng, Huang, Zhou, Li, & Wu, 2020, Meselson, 2020, Wang & Du, 2020, Ye et al., 2020, Zheng, 2020)	(Al Hosani et al., 2018, Alagaili et al., 2014, Azhar et al., 2014, Fung and Liu, 2019, Lim et al., 2016, Ye et al., 2020)

APN – aminopeptidase N, ACE2 – angiotensin-converting enzyme 2, DPP4 – dipeptidyl peptidase 4, ASA – 9-O-acetylated sialic a.