A DNA sequence encoding the SARS-CoV-2 (XBB.1.5) Spike RBD (YP_009724390.1, with mutation G339H, R346T, L368I, S371F, S373P, S375F, T376A, D405N, R408S, K417N, N440K, V445P, G446S, N460K, S477N, T478K, E484A, F486P, F490S, Q498R, N501Y, Y505H) (Arg319-Phe541) was expressed with a polyhistidine tag at the C-terminus. The mutations were identified in the SARS-CoV-2 variant (known as variant XBB.1.5).