Rapid in vitro assays for screening neutralizing antibodies and antivirals against SARS-CoV-2

Highlights • We have developed a rapid, accurate, and highly reproducible plaque reduction microneutralization (PRMNT) assay for SARS-CoV-2. • Our PRMNT assay allows to identify and characterize antibodies with neutralizing activity against SARS-CoV-2. • Likewise, our PRMNT assay can be used to find compounds with antiviral activity against SARS-CoV-2. • The PRMNT assay can be developed using peroxidase or infrared staining readouts. • Our PRMNT assay can be adapted to HTS settings to interrogate complex library of SARS-CoV-2 inhibitors.
Towards the end of 2019, a novel coronavirus (CoV) named severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), genetically similar to severe acute respiratory syndrome coronavirus (SARS-CoV), emerged in Wuhan, Hubei province of China, and has been responsible for coronavirus disease 2019 (COVID-19) in humans. Since its first report, SARS-CoV-2 has resulted in a global pandemic, with over 10 million human infections and over 560,000 deaths reported worldwide at the end of June 2020. Currently, there are no United States (US) Food and Drug Administration (FDA)-approved vaccines and/or antivirals licensed against SARS-CoV-2. The high economical and health impacts of SARS-CoV-2 has placed global pressure on the scientific community to identify effective prophylactic and therapeutic treatments for SARS-CoV-2 infection and associated COVID-19 disease. While some compounds have been already reported to reduce SARS-CoV-2 infection and a handful of monoclonal antibodies (mAbs) have been described that neutralize SARS-CoV-2, there is an urgent need for the development and standardization of assays which can be used in high through-put screening (HTS) settings to identify new antivirals and/or neutralizing mAbs against SARS-CoV-2. Here, we described a rapid, accurate, and highly reproducible plaque reduction microneutralization (PRMNT) assay that can be quickly adapted for the identification and characterization of both neutralizing mAbs and antivirals against SARS-CoV-2. Importantly, our MNA is compatible with HTS settings to interrogate large and/or complex libraries of mAbs and/or antivirals to identify those with neutralizing and/or antiviral activity, respectively, against SARS-CoV-2.