In a recently published article, scientists have described the identification and therapeutic evaluation of an antibody that broadly neutralizes major variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), including the alpha, beta, delta, and omicron variants.
Introduction
In response to the deadly coronavirus disease, 2019 (COVID-19) caused by SARS-CoV-2, several potential vaccines, therapeutic antibodies, and antiviral drugs have been developed, which collectively helped reduce the pandemic trajectory. However, continuous emergence of novel viral variants with increased transmissibility and immune fitness has highlighted the need for developing broad-spectrum therapeutic and preventive interventions that can neutralize a wide variety of viral variants.
Most monoclonal therapeutic antibodies developed during the early pandemic phase work by preventing the interaction between the SARS-CoV-2 spike protein and human angiotensin-converting enzyme 2 (ACE2), which is the key step for viral entry into host cells. These antibodies mostly target epitopes in the receptor-binding motif (RBM) of the spike receptor-binding domain (RBD).
The most recently emerged SARS-CoV-2 omicron variant contains more than 15 mutations in the spike RBD, which makes the variant highly resistant to monoclonal as well as vaccine-induced antibodies. To better manage the pandemic, it is vital to develop broadly neutralizing antibodies against immune evasive variants like omicron.
In the current study, scientists have described the identification and therapeutic evaluation of a monoclonal antibody with broad neutralizing efficacy against SARS-CoV-2 variants.
Therapeutic Efficacy of SW186
The therapeutic efficacy of the antibody was tested by initially infecting the mice with alpha, beta, or delta variant of SARS-CoV-2, followed by treatment with the SW186 antibody. The findings revealed that mice treated with SW186 antibodies have a significantly lower viral load in the lungs compared to untreated mice. Moreover, the antibody treatment protected the mice against body weight loss, lung injury, and lung infiltration of inflammatory mediators.
To test the efficacy of the SW186 antibody in humans, a panel of humanized antibodies was generated and tested for neutralizing efficiency against alpha, beta, and delta variants. The findings revealed that most of these humanized antibodies neutralize the tested variants with similar efficacy as the murine SW186 antibody.
Conclusion
The study identifies a broad-spectrum monoclonal antibody (SW186) that efficiently neutralizes SARS-CoV-2 variants of concern and SARS-CoV-1. The scientists believe that the conserved RBD epitope targeted by SW186 antibody could be considered in future studies for developing novel therapeutic antibodies.
Source:
https://www.news-medical.net/news/20220805/Study-identifies-broad-spectrum-antibody-that-neutralizes-SARS-CoV-2-variants-of-concern.aspx