The mouse monoclonal antibody is produced from a hybridoma resulting from fusion of SP2/0 myeloma and B-lymphocytes obtained from a mouse immunized with Spike RBD. The antibody is specific against the Omicron (B.1.1.529/BA.1) variant of SARS-CoV-2, and has no binding with the spike RBD of the wild type virus and other viral lineages.