Human antibodies can neutralize SARS-CoV-2.

In this preprint, Ju et al. demonstrate the existence of virus-specific memory B cells recognizing the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein in patients infected with SARS-CoV-2. They observed crossreactivity of antibodies from patients infected with SARS-CoV-2 against spike proteins, but not against the RBD, of SARS-CoV-1 and MERS-CoV. Through single-cell sorting and BCR sequencing, they generated 206 SARS-CoV-2 RBD-specific monoclonal antibodies. Antibodies were from diverse families of immunoglobulin genes, without any apparent enrichment for specific families. Only two clones showed 98–99% blocking of viral entry, which correlated with high competing capacity against ACE2 receptor. These results indicate that the humoral response is virus specific and diverse and can produce potent neutralizing antibodies.