Passive antibody therapy in COVID-19

Abstract

For over a century, transfusion of convalescent plasma from recovered individuals has been tried as a therapeutic approach when a novel pathogen emerges. As the world awaits SARS-CoV-2 vaccines to be tested and safely deployed, the rapidity with which antiviral monoclonal antibodies can be isolated and engineered offers an attractive alternative option for passive immunization.

Fig. 1. Potential mechanisms of coronavirus antibody neutralization and antibody enhancement of infection.

a | Mechanism 1: neutralizing antibodies could block viral infection by binding to the viral spike protein and preventing it from interacting with the cellular receptor angiotensin-converting enzyme 2 (ACE2). Mechanism 2: neutralizing antibodies could bind to the viral spike protein and block the conformational changes that the spike protein must undergo to facilitate fusion of the viral and host cell membranes. b | Antibodies could enhance viral entry into immune cells by binding to the viral spike protein with their Fab portion and to Fc receptors (FcRs) with their Fc domain.