Two super antibodies have been discovered that block the entry of the Sars-Cov-2 virus into cells: they act with slightly different mechanisms and, when administered in small doses, individually or together, they are able to prevent infection in mice. The result, which paves the way for new antibody cocktail-based therapies, is published in Science by an international group led by the University of Washington.

Massimo Galli, Agostino Riva and Arianna Gabrieli from the Sacco Hospital in Milan also participated in the study.According to virologist Galli, the two new neutralizing antibodies, called S2E12 and S2M11, are “very promising for future developments in the treatment of Covid-19”, as he explains in a tweet. The researchers identified them by reviewing nearly 800 antibodies isolated from 12 patients who recovered from the infection. Their mechanism of action has been studied at the molecular level thanks to the super cryo-electron microscope (a technology awarded the Nobel Prize in chemistry in 2017).


In this way it was found that both S2E12 and S2M11 prevent the virus from attaching to the host cell’s Ace-2 receptor and do so with different and competing mechanisms of action. The S2M11 antibody, in particular, also manages to block the famous Spike protein that the virus uses as a key to enter the cell, effectively preventing infection. In addition to neutralizing the virus, the antibodies also appear to favor the reaction of specific immune cells that fight infections, helping them to eliminate the enemy.

“We think that exploiting multiple, different and complementary mechanisms of action allows us to have more benefits in clinical applications,” the study authors write. “Our results pave the way for the refinement of antibody cocktails for prophylaxis or therapy that could have the advantage of avoiding or limiting the emergence of mutant viruses capable of escaping the host’s defenses.”