Table 1.

WHO’S classification of SARS-CoV-2 Variants of Concern (March 2022): Who label, Pango lineage, local of origin, quantification and descriptions of spike mutations and important characteristics highlighted in the literature

WHO label	Pango lineage	Origin [90]	Number of mutations in spike	Spike mutations	Important characteristics
Beta	B.1.351	South Africa on May 2020	10 [106]	D80A, D215G, 241del, 242del, 243del, K417N, E484K, N501Y, D614G, A701V	- Enhanced transmissivity and higher mortality rates [107–109] - Evidence of non-protection against mild-to-moderate COVID-19 with two-doses of ChAdOx1 nCoV-19 vaccine/AstraZeneca-Oxford (multicenter, double-blind, randomized trial, n = 2026) [110] - Further evidence of immune escape was founded [102, 111, 112], and the infection by this variant might confer potent lineage-specifical and cross-reactive antibodies [113]
Alpha	B.1.1.7	UK on 20 September 2020	13 [106]	69del, 70del, 144del, E484K, S494P, N501Y, A570D, D614G, P681H, T716I, S982A, D1118H, K1191N	- Enhanced transmissivity [100, 114] - It might cause more severe illness [100, 115]
Delta	B.1.617.2	India on October 2020	15 [89]	T19R, V70Fa, T95I, G142D, E156-, F157-, R158G, A222Va, W258La, K417Na, L452R, T478K, D614G, P681R, D950N	- Increased transmissibility [116] - Immune evasion of response triggered by infection and vaccination, and also Bamlanivimab® [104, 117–119] - It might have a lower reduction in transmission after vaccination, compared to Alpha [120] - Some evidence of similar prevalence between vaccinated and unvaccinated groups (n = 539) [121]
Gamma	P.1 or B.1.1.28.1	Brazil on November 2020	11 [106]	L18F, T20N, P26S, D138Y, R190S, K417T, E484K, N501Y, D614G, H655Y, T1027I,	-Resistant to multiple neutralizing mAbs, convalescent plasma, and vaccinee sera [118, 122–124]
Omicron	B.1.1.529	South Africa on November 2021	34 [89]	A67V, del69-70, T95I, del142-144, Y145D, del211, L212I, ins214EPE, G339D, S371L, S373P, S375F, K417N, N440K, G446S, S477N, T478K, E484A, Q493R, G496S, Q498R, N501Y, Y505H, T547K, D614G, H655Y, N679K, P681H, N764K, D796Y, N856K, Q954H, N969K, L981F	- Potential of increased transmissibility [89] -Potential of reduction in neutralization by some EUA monoclonal antibody treatments [89] - Potential of reduction in neutralization by post-vaccination sera [89] Omicron’s mutation characteristics are further discussed in Tables 2, 3 and 4

^aMight be detected in some sequences but not all