Enhancement of SARS-CoV-2 infection and growth by an ACE2-specific monoclonal antibody

SARS-CoV-2 causes COVID-19 pandemic and continues to pose a threat to global public health through genetic mutation. In this study, we have found that an ACE2-specific monoclonal antibody at low concentration was able to greatly enhance SARS-CoV-2 infection and growth in cell culture. Strikingly, it promotes SARS-CoV-2 plaque formation, resulting in accurate titration of different SARS-CoV-2 variants, particularly the newly emerged Omicron variants, which otherwise cannot be determined by standard plaque assays. Quantification of infectious titers of the newly emerged variants will facilitate the development and evaluation of vaccines and antiviral drugs against SARS-CoV-2.