No treatment or vaccine currently exists for COVID-19, the disease caused by SARS-CoV-2. Recently published data from a mouse study suggest that a laboratory-created human antibody can neutralize SARS-CoV-2 and has potential as a therapeutic agent against the disease.

When infected by a pathogen such as a virus, the body mounts an immune response and produces antibodies against the invader. Antibodies bind to specific sites on the viral surface known as epitopes and signal the immune system to destroy the virus. Monoclonal antibodies are a specific type of antibody that is produced in the laboratory against a single epitope. These synthetic antibodies mimic the body’s immune system.

Previous research in SARS-CoV-1 has demonstrated that neutralizing antibodies can be created against the spike (S) glycoprotein that is involved in host cell entry. The spike proteins of the SARS-CoV-1 and SARS-CoV-2 viruses are 77 percent identical.The current study investigated whether antibodies generated against SARS-CoV-1 would also neutralize SARS-CoV-2.

In cell culture studies, researchers discovered that one antibody, 47D11, neutralized SARS-CoV-1 and SARS-CoV-2 and blocked the virus from infecting cells. The mechanism is not known but does not appear to involve interference with the virus’s ability to bind to its receptor, an important step in the path towards a treatment or vaccine.

These findings demonstrate that a human monoclonal antibody shows promise as a therapeutic strategy against COVID-19. Further clinical trials are needed to determine if these findings translate to humans.

• Link to full study.