Used in research and development of vaccines and therapeutic antibodies targeting the Omicron variant of SARS-CoV-2. The Fc tag enables easy detection and purification, making it valuable in immunoassays and binding studies. Widely applied in neutralization assays to evaluate efficacy of monoclonal antibodies and convalescent sera. Supports structural studies to understand spike protein interactions with host cell receptors. Also utilized in diagnostic kit development for detecting variant-specific immune responses.