Synthetic Antibodies neutralize SARS-CoV-2 infection of mammalian cells

ABSTRACT

Coronaviruses (CoV) are a large family of enveloped, RNA viruses that circulate in mammals and birds but have crossed the species barrier to infect humans seven times. Of these, three pathogenic strains have caused zoonotic infections in humans that result in severe respiratory syndromes including the Middle East Respiratory Syndrome (MERS-CoV), severe acute respiratory syndrome (SARS-CoV), and now SARS-CoV-2 coronaviruses, the latter of which is the cause of the ongoing pandemic of coronavirus disease 2019 (COVID-19). Here, we describe a panel of synthetic monoclonal antibodies, built on a human framework, that bind SARS-CoV-2 spike protein, compete for binding with ACE2, and potently inhibit infection by SARS-CoV-2. These antibodies were found to have a range of neutralization potencies against live virus infection in Vero E6 cells, potently inhibiting authentic SARS-CoV-2 virus at sub-nanomolar concentrations. These antibodies represent strong immunotherapeutic candidates for treatment of COVID-19.