Time Event Organization 2020.01.12 2019 novel coronavirus (2019-nCoV) WHO 2020.02.11 Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ICTV 2020.02.12 Coronavirus disease 2019 (COVID-19) WHO 2020.03.11 A pandemic WHO
Table 1. Related events of novel coronavirus.
Nucleotide sequence identity (%) Other coronaviruses Accession number References 96.2 Bat-RaTG13-CoV Not available Ceraolo and Giorgi 2020 89 Bat-SL-CoVZXC21 MG772934 Chan et al. (2020) 82 Human SARS-CoV BJ01 AY278488 Chan et al. (2020) 82 Human SARS-CoV Tor2 AY274119 Chan et al. (2020) 87.99 Bat-SL-CoVZC45 MG772933 Chen Yan et al. (2020) 80 SARS-CoV Not available Chen Yan et al. (2020) 90.23 Pangolin-CoV-2020 GWHABKW00000000 Liu P et al. (2020) 87.99 Bat-SL-CoVZC45 MG772933 Lu et al. (2020) 87.23 Bat-SL-CoVZXC21 MG772934 Lu et al. (2020) ~ 79 SARS-CoV Not available Lu et al. (2020) ~ 50 MERS-CoV Not available Lu et al. (2020) ≥ 88.2 Bat-SL-CoVZC45 MG772933 Malik et al. (2020) ≥ 88.2 Bat-SL-CoVZXC21 MG772934 Malik et al. (2020) 89.1 Bat-SL-CoVZC45 MG772933 Wu F et al. (2020) 80–98 Pangolin-CoV Not available Xiao et al. (2020) 91.02 Pangolin-CoV Not available Zhang T et al. (2020) 79.6 SARS-CoV BJ01 AY278488 Zhou P et al. (2020) > 85 Bat-SL-CoVZC45 MG772933 Zhu et al. (2020)
Table 2. Nucleotide sequence identity between SARS-CoV-2 and other coronaviruses.
Structural protein Protein length (aa) Location Function ( Boopathi et al. 2020) S protein 1273 21, 563..25, 384 Receptor binding and membrane fusion E protein 75 26, 245..26, 472 Virus invasion and reproduction M protein 222 26, 523..27, 191 Virus assembly N protein 419 28, 274..29, 533 Replication and transcription
Table 3. Protein length, location and function of S protein, E protein, M protein and N protein of SARS-CoV-2.
Origin Support Opposition Bat 1. SARS-CoV-2 has 96.2% homology with bat coronavirus (RTG13) (Zhou P et al. 2020)
2. SARS-CoV-2 is most closely related to two SARS-like coronavirus sequences isolated from bats (Chan et al. 2020; Malik et al. 2020; Zhang LS et al. 2020)
3. SARS-CoV-2 has 100% amino acid similarity to BAT-SL-CoVZC45 in nsp7 and E proteins (Wu F et al. 2020)
4. SARS-CoV-2 most likely originated from a bat SARS-like coronavirus by Bayesian phylogeographic reconstruction (Benvenuto et al. 2020)
5. SARS-CoV-2 can infect bat intestinal cells (Zhou J et al. 2020)
Unreported Pangolin 1. Pangolin coronavirus genomes have more than 85.5% similarity to SARS-CoV-2 (Lam et al. 2020; Xiao et al. 2020; Zhang et al. 2020f)
2. The amino acid identities of pangolin coronavirus and SARS-CoV-2 in the E, M, N and S genes were 100%, 98.2%, 96.7% and 90.4%, respectively (Xiao et al. 2020)
1. Phylogenetic analyses do not support that SARS-CoV-2 arose directly from Pangolin-CoV (Liu P et al. 2020) Snake 1. SARS-CoV-2 has the highest similarity with the synonymous codon usage bias of snakes (Zhou P et al. 2020) 1. The study has several limitations (Zhang C et al. 2020)
2. The ACE2 of snake lost the capability to associate with S protein (Luan et al. 2020)
Turtle 1. The interaction between the key amino acids of S protein RBD and ACE2 indicates that turtles may be a potential intermediate host for transmitting SARS-CoV-2 to humans (Liu Z et al. 2020) 1. The ACE2 of turtle lost the capability to associate with S protein (Luan et al. 2020) Mink 1. By comparing the infectivity patterns of all viruses hosted on vertebrates, mink viruses show a closer infectivity pattern to SARS-CoV-2 (Guo et al. 2020)
2. Minks turned out to be highly permissive for SARS-CoV-2 (Enserink 2020)
3. Minks were infected by SARS-CoV-2 (Oreshkova et al. 2020)
Unreported Ferret 1. SARS-CoV-2 can replicate in the upper respiratory tract of ferrets (Shi et al. 2020) Unreported Cat 1. Cats are highly susceptible to SARS-CoV-2 (Shi et al. 2020)
2. Cats acquire SARS-CoV-2 infection under natural conditions (Zhang Q et al. 2020)
3. Infected cats can spread SARS-CoV-2 from one cat to another (Halfmann et al. 2020)
Unreported Dog 1. Two dogs in Hong Kong are infected with SARS-CoV-2 (Sit et al. 2020) 1. Dogs have a low susceptibility to SARS-CoV-2 (Shi et al. 2020)
Table 4. Origin of SARS-CoV-2.