Used in vaccine development and diagnostic assays to detect neutralizing antibodies against the Omicron BA.2.75 variant of SARS-CoV-2. Serves as an antigen in serological testing to evaluate immune response in infected or vaccinated individuals. Employed in research studies to assess the binding affinity of therapeutic antibodies and entry inhibitors targeting the spike protein. Supports structural analysis to understand mutations affecting viral infectivity and immune evasion.