Recombinant SARS-CoV-2 Spike protein in its homotrimeric form, containing S1+S2 subunits and encompassing amino acids 16-1213. This protein corresponds to SARS-CoV-2 Variant B.1.1.529 BA.1 also known as variant Omicron originally identified in South Africa, and contains Omicron Spike mutations listed below. The construct also contains mutations 682RRAR685>A, K986P and V987P, and a T4 trimerization domain followed by a His-tag (6xHis) in C-terminal. The recombinant protein was affinity purified.