The SARS-CoV-2 Omicron Variant

The SARS-CoV-2 Omicron variant (B.1.1.529) was designated the fifth variant of concern (VOC) by the WHO in November, 2021 ⁽¹⁾. Its genome contains more than 50 mutations, including at least fifteen mutations in the spike protein receptor-binding domain (RBD). Omicron subvariants have replaced the previous VOCs and have become dominant across the planet due to enhanced transmissibility and immune evasion. Of the original five recognized Omicron subvariant designations (i.e., BA.1, BA.2, BA.3, BA.4, and BA.5), new lineages derived primarily from BA.2 and BA.4/5 are increasing in prevalence in different world regions.

Omicron BA.4/5 Subvariants BQ.1 and BF.7

BA.4/5 lineage subvariants account for about 77.1% of all Omicron-related lineages. BQ.1 and BF.7 are two of several BA.4/5 subvariants that are of particular concern, due primarily to their increased immune evasion and monoclonal antibody resistance capabilities. BF.7 acquired the R346T, and BQ.1 both the K444T and N460K, spike mutations. Recent work indicates that the N460K mutation plays a significant role in the enhanced neutralization resistance of BQ.1 ⁽²⁾. In addition, variant splintering, where distinct subvariants rise to dominance in different world regions, undermines unified vaccine design and treatment regimen plans.

GeneTex continues to expand its inventory of antibodies and recombinant proteins to support SARS-CoV-2 research. New additions are Omicron spike and nucleocapsid recombinant proteins for the BQ.1 and BF.7 lineages described above. The recombinant spike proteins are available in RBD only or ECD (Extracellular Domain) formats, with the ECD versions being trimeric. The His tag is located at the C-terminus. To learn more about these and other GeneTex reagents for Omicron research, please see the highlighted products below and visit our website at www.genetex.com.

Figure 1. Spike mutation sites in Omicron subvariants

Figure 2. Nucleocapsid protein mutation sites in Omicron subvariants

GeneTex has a wide range of recombinant antibody and protein reagents for Omicron research. Notably, nucleocapsid antibodies whose immunogens do not contain any Omicron mutation sites are shown in Figure 2.

Recombinant spike proteins (trimer) derived from different SARS-CoV-2 variants were assayed by indirect ELISA using the specified GeneTex monoclonal antibodies.

Highlighted Products

SARS-CoV-2 (COVID-19) Spike RBD Protein, Omicron / BF.7 variant, His tag (GTX137878-pro)

SARS-CoV-2 (COVID-19) Spike RBD Protein, Omicron / BQ.1 variant, His tag (GTX137879-pro)

SARS-CoV-2 (COVID-19) Spike (ECD) Protein, Omicron / BF.7 variant, His tag (GTX137880-pro)

SARS-CoV-2 (COVID-19) Nucleocapsid protein, Omicron / BQ.1 variant, His tag (GTX137883-pro)

SARS-CoV-2 (COVID-19) Spike (ECD) Protein, Omicron / BA.4 / BA.5 variant, His tag (GTX137113-pro)

SARS-CoV-2 (COVID-19) Spike RBD Protein, Omicron / BA.4 / BA.5 variant, His tag (GTX137098-pro)

SARS-CoV-2 (COVID-19) Spike RBD antibody [HL1014] (GTX635807)

SARS-CoV-2 (COVID-19) Spike RBD antibody [HL1004] (GTX635793)

Lateral Flow Assay (Recommended Nucleocapsid Antibody Pairs)

Antibody Pair   Product Name Clonality EC50 Cat. No. Pair I    Nucleocapsid antibody [HL5511] Rb recAb 14 pM GTX635689   Nucleocapsid antibody [HL448] Rb recAb 11 pM GTX635686 Pair II   Nucleocapsid antibody [HL5410] Rb recAb 9 pM GTX635685   Nucleocapsid antibody [HL455] Rb recAb 6 pM GTX635688

Reagents that detect Omicron

Product Name Applications Cat. No.   SARS-CoV-2 (COVID-19) Spike RBD antibody [HL257] WB, ICC/IF, IHC-P, ELISA, IHC-P (cell pellet) GTX635692   SARS-CoV-2 (COVID-19) Spike RBD ELISA Pair [HL1014 / HL1003] ELISA, Sandwich ELISA GTX500046   SARS-CoV-2 (COVID-19) Spike RBD Protein Sandwich ELISA Kit ELISA, Sandwich ELISA GTX536267   SARS-CoV-2 (COVID-19) Spike RBD Omicron antibody [HL1866] ELISA, Sandwich ELISA, Neutralizing/Inhibition GTX637591   SARS-CoV-2 (COVID-19) Spike RBD Omicron antibody [HL1867] ELISA, Sandwich ELISA, Neutralizing/Inhibition GTX637592 SARS-CoV-2 (COVID-19) Spike RBD antibody WB, ICC/IF, FACS, ELISA, Neutralizing/Inhibition, Sandwich ELISA, IHC-P (cell pellet) GTX135709   SARS-CoV-2 (COVID-19) Spike RBD antibody [HL1002] ELISA, Lateral Flow, Neutralizing/Inhibition, Sandwich ELISA GTX635791     SARS-CoV-2 (COVID-19) Spike RBD antibody [HL1003] ICC/IF, ELISA, Neutralizing/Inhibition, Sandwich ELISA GTX635792     SARS-CoV-2 (COVID-19) Spike RBD antibody [HL1003] (HRP) ELISA, Sandwich ELISA GTX635792-01    SARS-CoV-2 (COVID-19) Spike RBD antibody [HL1004] ICC/IF, ELISA, Neutralizing/Inhibition, Sandwich ELISA GTX635793    SARS-CoV-2 (COVID-19) Spike RBD antibody [HL1004] (HRP) ELISA, Sandwich ELISA GTX635793-01   SARS-CoV-2 (COVID-19) Spike RBD antibody [HL1014] ICC/IF, ELISA, Sandwich ELISA GTX635807    SARS-CoV-2 (COVID-19) Spike RBD antibody [GT5449] WB, ELISA, Sandwich ELISA GTX636042   SARS-CoV / SARS-CoV-2 (COVID-19) spike antibody [1A9] WB, ICC/IF, IHC-P, FACS, IP, ELISA, EM, Sandwich ELISA, IHC-P (cell pellet) GTX632604    SARS-CoV-2 (COVID-19) Nucleocapsid ELISA Pair [HL5511 / HL448] ELISA, Sandwich ELISA GTX500045   SARS-CoV-2 (COVID-19) Nucleocapsid antibody [HL344] WB, ICC/IF, IHC-P, IHC-Fr, ELISA, Sandwich ELISA, IHC-P (cell pellet) GTX635679     SARS-CoV-2 (COVID-19) Nucleocapsid antibody [HL5410] WB, ICC/IF, ELISA, Lateral Flow, Sandwich ELISA, IHC-P (cell pellet) GTX635685    SARS-CoV-2 (COVID-19) Nucleocapsid antibody [HL448] WB, ICC/IF, IHC-P, ELISA, Lateral Flow, Sandwich ELISA, IHC-P (cell pellet) GTX635686     SARS-CoV-2 (COVID-19) Nucleocapsid antibody [HL448] (HRP) WB, ELISA, Sandwich ELISA GTX635686-01    SARS-CoV-2 (COVID-19) Nucleocapsid antibody [HL453] WB, ICC/IF, ELISA, IHC-P (cell pellet) GTX635687    SARS-CoV-2 (COVID-19) Nucleocapsid antibody [HL455] WB, ICC/IF, ELISA, Lateral Flow, Sandwich ELISA, IHC-P (cell pellet) GTX635688    SARS-CoV-2 (COVID-19) Nucleocapsid antibody [HL5511] WB, ICC/IF, ELISA, Lateral Flow, Sandwich ELISA, IHC-P (cell pellet) GTX635689     SARS-CoV-2 (COVID-19) Nucleocapsid antibody [HL455-MS] WB, ICC/IF, ELISA, Sandwich ELISA, IHC-P (cell pellet) GTX635712     SARS-CoV-2 (COVID-19) Nucleocapsid antibody [GT113] WB, ICC/IF, ELISA, Sandwich ELISA GTX635808   SARS-CoV-2 (COVID-19) Spike S1 antibody [GT263] WB, ICC/IF, ELISA, Sandwich ELISA, IHC-P (cell pellet) GTX635708   SARS-CoV-2 (COVID-19) Spike S1 antibody [HL13402] WB, ICC/IF, ELISA, Sandwich ELISA GTX635713    SARS-CoV-2 (COVID-19) Spike S2 antibody [HL237] WB, ICC/IF, ELISA, Sandwich ELISA, IHC-P (cell pellet) GTX635693    SARS-CoV-2 (COVID-19) Spike S2 antibody [HL1038] WB, ICC/IF, ELISA, Sandwich ELISA, IHC-P (cell pellet) GTX635910   SARS-CoV-2 (COVID-19) Spike S2 / S2' antibody [HL1039] WB, ICC/IF, ELISA, Sandwich ELISA, IHC-P (cell pellet) GTX635911   SARS-CoV-2 (COVID-19) Spike S2 antibody [GT745] WB, ELISA, Sandwich ELISA, IHC-P (cell pellet) GTX636037   SARS-CoV-2 (COVID-19) Spike S2 antibody [GT8110] WB, ELISA, Sandwich ELISA, IHC-P (cell pellet) GTX636038

References:

1. World Health Organization

2. bioRxiv. 2022 Oct 20;2022.10.19.512891. doi: 10.1101/2022.10.19.512891. Preprint