Recombinant SARS-CoV-2 S-trimer Protein is produced by our Mammalian expression system and the target gene encoding Ser13-Gln1208 is expressed with a 6His tag at the C-terminus. T19I, LPPA24S, G142D, V213G, G339D, S371F, S373P, S375F, T376A, D405N, R408S, K417N, N440K, S477N, T478K, E484A, Q493R, Q498R, N501Y, Y505H, D614G, H655Y, N679K, P681H, N764K, D796Y, Q954H and N969K mutations were identified in the SARS-CoV-2 variant (known as BA.2 lineage) which emerged in the United Kindom. Six proline substitutions and furin cleavage site substitutions are introduced to stabilize the trimeric prefusion state of SARS-CoV-2 S protein and abolish the furin cleavage site, respectively.