SARS-CoV-2 Variant Classifications and Definitions – Centers for Disease Control and Prevention (.gov)

WHO Label:  Omicron

Pango Lineage: B.1.1.529, BA.1, BA.1.1, BA.2, BA.3, BA.4 and BA.5 lineages (Pango lineageexternal icon)a

Spike Protein Substitutions:  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

Nextstrain clade (Nextstrainexternal icon)b: 21K

First Identified: South Africa


  • Potential increased transmissibility
  • Potential reduction in neutralization by some EUA monoclonal antibody treatments
  • Potential reduction in neutralization by post-vaccination sera