A DNA sequence encoding the SARS-CoV-2 (BA.1) Spike S1+S2 trimer (YP_009724390.1, with mutations A67V, del69-70, T95I, G142D, del143-145, N211I, del212, G339D, R346K, S371L, S373P, S375F, S477N, T478K, E484A, Q493R, G496S, Q498R, N501Y, Y505H, T547K, D614G, H655Y, N679K, P681H, R682G, R683S, R685S, N764K, D796Y, F817P, N856K, A892P, A899P, A942P, Q954H, N969K, L981F, K986P, V987P and furin cleavage site mutants) was expressed with bacteriophage T4 fibritin and a C-terminal polyhistidine tag followed by an AVI tag. The mutations were identified in the SARS-CoV-2 variant (known as variant BA.1).The expressed protein was biotinylated in vivo by the Biotin-Protein ligase (BirA enzyme) which is co-expressed.