[Infectivity-enhancing antibodies against SARS-CoV-2]

Antibodies against the receptor binding domain of the spike protein of SARS-CoV-2 play an important role in preventing infection as neutralizing antibodies. However, antibodies that recognize a specific site on the N-terminal domain of the spike protein induce an open domain of receptor binding that increases the binding of ACE2 and enhances the infectivity of SARS-CoV-2. Furthermore, the presence of the infectivity-enhancing antibodies reduces the neutralizing activity of the neutralizing antibodies. Therefore, when considering the antibody response to SARS-CoV-2, it is necessary to consider not only neutralizing antibodies but also the balance between neutralizing and infectivity-enhancing antibodies. In this article, function and mechanism of infectivity-enhancing antibodies are introduced.