Specific variants of SARS-CoV-2 Sites of SARS-CoV-2 mutant & mechanisms Features (transmissible, infectious, and severe) Notes
Omicron variant
B.1.1.529 The S1-RBD/S2 mutation/deletion (the alterations of SARS-CoV-2 S RNA sequences) lead to escape immune surveillance. The 3.0 Å cryo-EM structure of the omicron spike protein shows extensive mutations in RBD regions. Key mechanisms: binding of the RBD of the viral spike protein with the ACE2 receptor in the host-cells, improved host-cell entry and the replication of the virus. +++ More infectious sites of SARS-CoV-2 and more than existed deadly Delta variants Spread globally, increased hospitalization, exhibited more severity for the young generation, invaded defense mechanism of natural immunity; Not responsive to the available vaccines, and significant resistance to current antibody therapies. Extraordinary potency in immune escape compared to the other variants On Nov 26th 2021, WHO designated the new SARS-CoV-2 strain – named Omicron, from letter ”όμικρον” in the Greek alphabet – as a variant of concern (B.1.1529 variant) RBD: the receptor-binding domain; ACE2: the angiotensin-converting enzyme 2.
Delta variant
B.1.617.2 Arginine-203→methionine (R203M) mutations; Delta T478K substitution plays a vital role in stabilizing and reshaping the RBM loop473-490.
++
A
Beta and Kappa variants
B.1.351 Efficiently interact with ACE2 receptor
+
Alpha variant
B.1.1.7 Tthe S1-RBD/S2 mutation/deletion
+
Others new variants (recombinant variant)
XE Omicron (BA.1- BA.2) XD Delta-Omicron (BA.1) XF Delta-Omicron (BA.1) 637 cases in UK 49 cases in France or globe 38 cases in UK
wild-type (WT) The progenitor variant S (D614G) or G614 spikes (wt-S614G) +/-