In other words, there may be many nAbs to S but we failed to isolate them because of the selecting antigen, (2) the recombinant S protein that we used is close to native but non-neutralizing antibodies bind to sites on S that do not interfere with viral entry, (3) the S protein in natural infection disassembles readily generating a strong Ab response to “viral debris” that is non-neutralizing because the antibodies recognize protein surfaces that are not exposed on the native spike. Here, PROS1 is linked to infection.