SARS-CoV-2 recognizes hACE2 with comparable affinity to SARS-CoV

The binding affinity of SARS-CoV for hACE2 correlates with the overall rate of viral replication in distinct species as well as with transmissibility and disease severity. Indeed, specific SB mutations enabled efficient binding to hACE2 of SARS-CoV isolates from the three phases of the 2002-2003 epidemic, which were associated with marked disease severity. In contrast, SARS-CoV isolates detecting during the brief 2003-2004 re-emergence interacted more weakly with hACE2 and had low pathogenicity and transmissibility.