Fig. 2From: Convalescent plasma for adults with acute COVID-19 respiratory illness (CONCOR-1): study protocol for an international, multicentre, randomized, open-label trialPossible mechanisms of action of passively transferred antibodies in COVID-19. These include viral neutralization, complement-mediated antibody-dependent virolysis, antibody-dependent enhancement of immune response, antibody-mediated presentation of antigen, and antibody-dependent cell cytotoxicity. Of these, only viral neutralization is measured by neutralization assays currently used to qualify convalescent plasmaBack to article page