Table 1. Epidemiology, biological characteristics, and vaccine studies of SARS-CoV, MERS-CoV, and SARS-CoV-2.
| SARS | MERS | COVID-19 | |||
|---|---|---|---|---|---|
| Emergence | 2002 Nov | 2012 Jun | 2019 Nov | ||
| Guangdong, China | The Kingdom of Saudi Arabia | Wuhan, China | |||
| Areas affected [No. of countries] | China, Hong Kong, etc. [29 countries] | Middle East, Korea, etc. [27 countries] | Worldwide [216 countries] | ||
| Cases (Death, case fatality rate) | 8,096 (774, 9.6%) (10) | 2,519 (866, 34.3%) (17) | 9.4 million (482,730, 5.1%) (34) | ||
| Common symptoms | Fever, dry cough, shortness of breath, myalgia (11) | Fever, cough, shortness of breath, diarrhea, nausea vomiting (19) | Fever, dry cough, shortness of breath or difficulty breathing, loss of smell or taste (43,44,45) | ||
| Etiologic agents | SARS-CoV | MERS-CoV | SARS-CoV-2 | ||
| Reservoirs → Intermediate hosts | Bats → Palm civets (56) | Bats (24) → Dromedary camels (23) | Bats (35) → Snakes (?) (36), pangolins (?) (37) | ||
| Host receptor | ACE2 (13) | DPP4 (27) | ACE2 (38,39,40) | ||
| Animal models | Mice (C57BL/6, BALB/c, 129S) (57,58), aged mice (59,60,61), hACE2 transgenic mice (62,63), knock-out mice (MyD88, STAT1, Rag1, etc.) (57,58,64,65), golden Syrian hamsters (66), ferrets (67,68), NHPs (rhesus macaques, cynomolgus macaques, African green monkeys, common marmosets, squirrel monkeys, and mustached tamarins) (69,72) | rAd-hDPP4-transduced mice (73), hDPP4 transgenic (74,75,76) or knock-in mice (77,78), camelid (76,79,80), NHPs (rhesus macaques, common marmosets) (76,81,82,83) | hACE2 transgenic mice (84), golden Syrian hamsters (85), ferrets (86,87), NHPs (rhesus macaques, cynomolgus macaques) (88,89), rAd-hACE2-transduced mice (90) | ||
| Vaccines | |||||
| Live-attenuated virus vaccine | rSARS-CoV-ΔE (91,92), nsp16 mutant SARS-CoV (D130A) (93) | rMERS-CoV-ΔE (94), nsp16 mutant MERS-CoV (D130A) (95), MERS-CoV-Δ3, MERS-CoV-Δ4ab, MERS-CoV-Δ5 (94) | - | ||
| Inactivated whole-virus vaccine | Inactivated with UV light (96,97), formaldehyde (97), or β-propiolactone (98) | Inactivated by gamma (γ) irradiation (99) or formaldehyde (100) | Inactivated with β-propiolactone (PiCoVacc) (101) | ||
| Inactivated SARS-CoV-2* | |||||
| - Phase 1/2: ChiCTR2000031809 | |||||
| - Phase 1/2: ChiCTR2000032459 | |||||
| - Phase 1: NCT04412538 | |||||
| Inactivated SARS-CoV-2 with alum* | |||||
| - Phase 1/2: NCT04352608 | |||||
| - Phase 1/2: NCT04383574 | |||||
| Recombinant protein | Recombinant S, S1, RBD, trimeric form of S and RBD proteins (102,103,104,105,106) | Recombinant S, RBD, trimeric RBD, NTD proteins (107,108,109,110,111,112,113,114,115), S protein nanoparticles (116,117,118) | S protein nanoparticles with Matrix-M* | ||
| - Phase 1/2: NCT04368988 | |||||
| Virus-like particle | VLP exhibiting S, M, and E proteins (119,120,121) | VLP exhibiting S, M, and E proteins (123) | - | ||
| Chimeric VLP consisting of S and influenza M1 (122) | |||||
| DNA vaccine | S, S1, RBD, N antigens (98,124,125,126,127,128) | S, S1 antigens (114,129,130) | S Ag (131,132) | ||
| INO-4800* | |||||
| - Phase 1: NCT04336410 | |||||
| GX-19† | |||||
| - Phase 1/2a: NCT04445389 | |||||
| RNA vaccine | No investigated vaccine | No investigated vaccine | Lipid nanoparticle (LNP) encapsulated mRNA-1273* | ||
| - Phase 1: NCT04283461 | |||||
| - Phase 2: NCT04405076 | |||||
| 3LNP mRNA-BNT162* | |||||
| - Phase 1/2: 2020-001038-36 | |||||
| - Phase 1/2: NCT04368728 | |||||
| LNP-nCoVsaRNA* | |||||
| - Phase 1: ISRCTN17072692 | |||||
| Viral vector-based vaccine | rAd/S or N, rMVA/S (98,133,134,135) | Human rAdV/S, chimpanzee rAdV (ChAdOx1)/S, rMVA/S or N (136,137,138,139,140,141,142,143,144,145,146,147) | rAd5/S* | ||
| - Phase 1: ChiCTR2000030906 | |||||
| - Phase 2: ChiCTR2000031781 | |||||
| ChAdOx1-S* | |||||
| - Phase 1/2: 2020-001072-15 | |||||
| - Phase2b/3: 2020-001228-32 | |||||
| - Phase 3: ISRCTN89951424 | |||||
| Gam-COVID-Vac and Gam-COVID-Vac Lyo* | |||||
| - Phase 1: NCT04436471 | |||||
| - Phase 1: NCT04437875 | |||||
The list of clinical trials for COVID-19 vaccine has been adopted from *the database of the World Health Organization (148) and †the U.S National Library of Medicine (www.ClinicalTrials.gov).