To determine whether pseudotyped viruses expressing SARS-CoV-2 S proteins were comparable to replication-competent SARS-CoV-2 viruses in neutralization assays, the anti-spike monoclonal antibody (mAb, Specifica clone #41) targeting the RBD domain at different concentrations was incubated with viruses for 1 h at 37 °C prior to infection of HeLa-hACE2 cells (for pseudotyped luciferase viruses) or Vero E6 cells (for replication-competent SARS-CoV-2 with mNeonGreen). The gene discussed is PROS1; the disease is infection.