Highly regarded commentary on Covid antibodies from Scientific American
"Even if the antibodies stick around in the body, however, it is not yet certain that they will prevent future infection. What we want, Bowdish says, are neutralizing antibodies. These are the proteins that reduce and prevent infection by binding to the part of a virus that connects to and “unlocks” host cells. They are relatively easy to detect, and they are far easier for vaccine developers to generate than the alternative: the immune system’s T cells. In contrast, nonneutralizing antibodies still recognize parts of the pathogen, but they do not bind effectively and so do not prevent it from invading cells."