Used in vaccine development and diagnostic assays to detect neutralizing antibodies against the Omicron BA.2 variant of SARS-CoV-2. Serves as an antigen in immunoassays for measuring immune response in infected or vaccinated individuals. Employed in research studies to evaluate the efficacy of therapeutic antibodies and antiviral drugs targeting the spike protein. Supports structural studies to understand virus-receptor interactions and mechanisms of immune evasion.