A Swiss-American team has discovered a “promising” antibody against the new coronavirus, a discovery stemming from research into the 2003 SARS epidemic, according to an article published Monday in the scientific journal Nature.
This “human monoclonal antibody” was selected from the blood of a patient affected by the SARS virus, which is a cousin of SARS-CoV-2 at the origin of the current pandemic.
“Broad neutralizing activity”
This neutralizing antibody “holds the promise of an effective antidote to limit the Covid-19 pandemic,” according to this article.
The team mainly made up of researchers from the Swiss biotech Humabs Biomed (subsidiary of the American Vir Biotechnology) and the American University of Washington in Seattle (west), succeeded in selecting a monoclonal antibody which shows “a broad neutralizing activity against multiple sarbecoviruses including SARS-CoV-2 “.
Sarbecoviruses constitute a category of coronaviruses of which SARS-CoV-2 is part of the current pandemic and the virus responsible for the SARS epidemic between 2002 and 2004.
Selected from 25 other antibodies
The human monoclonal antibody baptized “S309” was selected from 25 other antibodies collected in 2004 and then in 2013 in the blood of the same patient who suffered from SARS.
S309 works by recognizing an “epitope” (remarkable molecule) on the surface of the SARS-CoV-2 virus which is “distinct” from the structure by which it binds to the ACE2 receptors of human cells. This epitope is relatively well preserved between different viruses of this category, in particular in that of SARS, which would explain the all-terrain character of the antibody against different sarbecoviruses.
Cocktail with two other antibodies
The team assisted for part of the work by the Structural Virology Unit (Institut Pasteur / CNRS) also found that a cocktail combining S309 with two other antibodies, had an “improved neutralizing power” compared to using only S309.
Such combined use could “mitigate the risk” of the emergence of viral resistance against this type of treatment, say the researchers.
“Our data indicate the potential discovery of powerfully neutralizing monoclonal antibodies against sarbecoviruses (…) and paves the way for a better response” in the event of new epidemics caused by this type of virus, conclude the researchers.
Discovery of a non-human antibody announced in early May
A Dutch team announced in early May in Nature the selection of a monoclonal antibody capable of neutralizing the SARS-CoV-2 virus in the laboratory. But it was a non-human antibody produced in the laboratory from cell lines.
–
