In vitro and in vivo functions of SARS-CoV-2 infection-enhncing and neutralizing antibodies

Several neutralizing antibodies against the receptor-binding domain (RBD) of spike protein showed Fc receptor-mediated enhancement of SARS-CoV-2 infection in culture cells, and those against the N-terminal domain (NTD) showed Fc receptor-independent enhancement of viral infection. However, both types of infection-enhancing antibodies protected mice and monkeys from SARS-CoV-2 infection, although very few monkeys showed slightly more severe symptoms. Thus, infection-enhancing antibody observed in in vitro experiment does not directly contribute to the enhancement of viral pathogenesis in animals.