Nevertheless, these conserved sites in the context of natural infection of SARS-CoV-2 just induced four potent cross-neutralizing mAbs (P10-6G3 targeting site S2, P07-4D10 targeting site S3, and P05-5B6 and P05-6H7 targeting site S4) against SARS-CoV and SARS-CoV-2, since most cross-binding nAbs showed obviously weaker affinity for SARS-CoV S protein than SARS-CoV-2 S protein, leading to inability to achieve cross-neutralization (Figures 3C–G). Here, PROS1 is linked to infection.