- Researchers working on monoclonal antibody treatment for the novel coronavirus have identified an antibody in a SARS survivor that can also neutralize SARS-CoV-2 and prevent COVID-19.
- The SARS antibody can be used in an antibody cocktail drug to prevent the new virus from attaching itself to cells and boost the immune response.
- Vir Biotechnology and GlaxoSmithKline will study two versions of the antibody in clinical trials.
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The race to find a cure for the novel coronavirus is on, and there are three separate efforts being pursued.
The simplest one is to use common drugs to treat symptoms and prevent complications. Such drugs include remdesivir, which was proven to reduce the COVID-19 recovery time, and blood thinners, which can prevent clotting-related complications, including strokes, heart attacks, and death. One other course of treatment concerns vaccines, which could be ready as early as September, to prevent the infection, though vaccines might not work, and there’s no guarantee they will actually roll out earlier than next year. The third option consists of brand new drugs that are being developed to stop the virus from replicating inside the body and improve the patient’s condition. These are antibody drugs that would work just like a plasma transfusion from a patient who survived COVID-19. They could also provide limited immunity, some researchers believe.
We’ve seen an increasing number of reports detailing the various monoclonal antibody drugs, with several such drugs already in development in China, Korea, and the US. The latest study details an unusual but exciting discovery: An antibody from a patient who survived SARS 17 years ago works against SARS-CoV-2.
SARS is another coronavirus, and it caused the 2003 outbreak that took the lives of 774 people of a total of 8,098 cases around the world. The novel coronavirus is its successor, which explains the name chosen for the virus that causes COVID-19.
A person who survived SARS developed an antibody that researchers call S309 in a new study published in Nature magazine (via LiveScience). The study was conducted by doctors from the University of Washington, Pasteur Institute in France, Università della Svizzera Italiana, Switzerland, and Vir Biotechnology. If Vir sounds familiar, that’s because it’s one of the US companies that’s currently looking to develop monoclonal antibodies for COVID-19.
The S309 antibody, found in the blood of that person, showed a strong ability to bind to the novel coronavirus’s spike protein, which is the key virus component of both SARS and SARS-CoV-2 that allows these two viruses to attach themselves to cells and invade them. Without this process, the virus can’t enter the cell to replicate itself, and a patient wouldn’t get COVID-19 even after contracting the virus.
Lab experiments show that S309 can bind itself to the spike protein, but testing on humans will be required to see whether the antibody is effective and safe. S309 is just one of the 25 SARS monoclonal antibodies found in blood from the patient, including samples taken in 2004 and 2013.
The researchers identify S309 as the most potent SARS neutralizing antibody that can block the novel coronavirus, but say it may be combined with additional SARS antibodies that had a weaker activity against SARS-CoV-2 to form a cocktail that could provide added protection.
Vir said in a separate announcement that two drugs featuring genetically engineered versions of the S309 antibody will be used in clinical tests in partnership with GlaxoSmithKline. These are known as VIR-7831 and VIR-7832. The first is supposed to have an extended half-life, while the second has an extended half-life and is supposed to function as a T cell vaccine, according to the company.
“Remarkably, we believe S309 likely covers the entire family of related coronaviruses, which suggests that, even as SARS-CoV-2 continues to evolve, it may be quite challenging for it to become resistant to the neutralizing activity of S309,” Vir Chief Scientific Officer Herbert Virgin said in a statement. “In addition, S309 exhibits potent effector function in vitro, potentially allowing the antibody to engage and recruit the rest of the immune system to kill off already infected cells. We have seen in animal models of other respiratory infections, such as influenza, that effector function significantly enhances the activity of antibodies that are already potently neutralizing.”