The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has infected over 425 million globally and caused more than 5.5 million deaths worldwide. The virus has evolved rapidly with multiple variants of concern (VOCs) arising including: B.1.1.7 (Alpha), B.1.351 (Beta), P.1 (Gamma), B.1.617.2 (Delta), and B.1.1.529 (Omicron) variants.
Making use of the trimeric (S) glycoprotein, SARS-CoV-2 (S) enters host cells. The (S) glycoproteins consists of two subunits, whereby one of them, the S1 subunit, binds to the angiotensin-converting enzyme 2 (ACE2) receptor present on the surface of host cells, whereas the S2 subunit fuses the membrane. Mutations are commonly found in the N-terminal domain (NTD) and the receptor-binding domain (RBD), and this allows for serum neutralising antibodies, as well as NTD- and RBD-directed monoclonal antibodies, to escape from infected or vaccinated patients.
In a new study, Du, et al., have identified a neutralising monoclonal antibody in humans, 87G7, against SARS-CoV-2 which has shown widespread neutralisation and immunisation efficacy against SARS-CoV-2 VOCs (Figure 1). The antibody works by inhibiting the binding of SARS-CoV-2 to ACE2 binding. This study provides great insight into the use and development of monoclonal antibodies for therapeutic and preventive therapy of individuals not previously exposed to SARS-CoV-2.
Using monoclonal antibodies as a prophylaxis and treatment of COVID-19 is made difficult by the ability of SARS-CoV-2 to mutate and change its antigenic profile. This however, may be a great step in the right direction in being able to fight the virus without being affected by these mutations.
NB to note: bioRxiv is a preprint server which publishes preliminary scientific reports that are not peer-reviewed and, therefore, should not be regarded as conclusive, or guide clinical practice or treated as established information.
Journal article: Du, W, et al., 2022. An ACE2-blocking antibody confers broad neutralization and protection against Omicron and other SARS-CoV-2 variants. bioRxiv.
Summary by Stefan Botha