Striking Antibody Evasion Manifested by the Omicron Variant of SARS-CoV-2

Methods Serum samples Convalescent plasma samples were obtained from patients with documented SARS-CoV-2 infection approximately one month after recovery or later. These samples were collected at the beginning of the pandemic in early 2020 at Columbia University Irving Medical Center, and therefore are assumed to be infection by the wild-type strain of SARS-CoV-2 4 . Sera from individuals who received two or three doses of mRNA-1273 or BNT162b2 vaccine were collected at Columbia University Irving Medical Center at least two weeks after the final dose. Sera from individuals who received one dose of Ad26.COV2.S or two doses of ChAdOx1 nCov-19 were obtained from BEI Resources. Some individuals were also infected by SARS-CoV-2 in addition to the vaccinations they received. Note that, whenever possible, we specifically chose samples with high titers against the wild-type strain of SARS-CoV-2 such that the loss in activity against B.1.1.529 could be better quantified, and therefore the titers observed here should be considered in that context. All collections were conducted under protocols reviewed and approved by the Institutional Review Board of Columbia University. Additional information for the vaccinee samples can be found in Extended Data Table 1 . Monoclonal antibodies Antibodies were expressed as previously described 22 , by synthesis of VH and VL genes (GenScript), transfection of Expi293 cells (Thermo Fisher), and affinity purification from the supernatant by..