Table 1.

A summary of the characteristics of variants of concern (VOCs).

	B.1.1.7	B.1.351	B.1.617.2	P.1
WHO Label	Alpha [30]	Beta [13]	Delta [62]	Gamma [65]
Country First Detected	England [30]	South Africa [13]	India [56]	Brazil [65]
First Detected	September 2020	October 2020	December 2020	December 2020
Spike mutations	69–70HV and 144Y deletions, N501Y, D614G, A570D, P681H, T716I, S982A, D1118H [33] E484K, S494P, and K1191N (found in some sequences) [35]	L242–244 deletions, A701V, D215G, D80A, D614G, E484K, K417N, N501Y, R246I, L18F [50]	156–157 deletions, D614G, D950N, L452R, T19R, T478K, P681R, R158GG142D (Found in some) [62]	K417T, E484K, N501Y, L18F, T20N, P26S, D138Y, R190S, D614G, H655Y, V1176F, T1027I [67]
Transmissibility	43–82% more transmissible [30]	50% more transmissible [53]	60% more transmissible [61]	Some studies reported 1.7–2.5 times more transmissible [65,74,75]
Viral Load	High [23,36] No difference [38]	High [49]	High in animal model [63]	High in reinfection case [15]
Duration of Infection	Long [26]	N/A	N/A	N/A
Hospitalization	High [32,39]	High [32]	High [61]	High [32,74]
Mortality	Increase [25,40]	Increase [52]	N/A	Increase [65]
Severity	No change [38,42,43]	N/A	N/A	N/A
Risk of reinfection	Not higher [42]	High [51,76]	N/A	6.4% [74]
Resistant to antibody neutralization	Resistant to most a mAbs directed against b NTD and slightly resistant to some mAbs directed against the c RBD [44]	Resistant to most mAbs directed against NTD and many mAbs directed against the RBD [44]	N/A	Resistant to some mAbs directed against RBD [69]
Resistance against convalescent plasma and sera	Less resistant [11,44]	More resistant [11,44,77]	N/A	Less resistant than B.1.351 [44,78]
Vaccine efficacy	Minimal impact [21,22]	Decrease for Pfizer [33], Moderna [79], Novavax, Johnson & Johnson [80,81,82], AstraZeneca [82,83]	2 doses of Pfizer [84,85,86] or AstraZeneca [84] is still protective	Decrease for CoronaVac [87]

^a mAbs: monoclonal antibodies. ^b NTD: N-Terminal domain. ^c RBD: receptor binding domain.