Twin antibodies identified that may help fight Covid-19

BEIJING: Scientists have identified a pair of neutralizing antibodies, isolated from a patient who recovered from Covid-19, that may offer therapeutic benefits and help design molecule antivirals and vaccine candidates to fight the SARS-CoV-2 virus.

Antibodies identified by the researchers, including those from Chinese Academy of Sciences , bind to the SARS-CoV-2 virus glycoprotein spike, blocking the spike's ability to bind to humans and mediate viral entry into host cells.

The researchers said preliminary testing of the two named antibodies, in one mouse model, resulted in a reduction in virus titers.

The finding, published in the journal Science, suggests that the antibodies may offer therapeutic benefits, in addition to informing the design of small-molecule therapies and vaccine candidates to fight Covid-19, they said.

Researcher Yan Wu from China and colleagues discovered that antibodies can simultaneously bind to different epitopes in the spike receptor binding domain (RBD).

Due to this binding, both antibodies together can confer a stronger neutralizing effect than either antibody alone, a prediction supported by in vitro experiments, they said.

This feature also means that if one of the viral epitopes mutates in a way that prevents the binding of one of the two antibodies, the other may still retain its neutralizing activity, according to the researchers.

By imaging the structure of the B38-linked viral peak RBD, the team confirmed that the antibody binds to a subset of the ACE2-linked amino acids, they said.

This, the researchers explained, provides an explanation for why the B38 antibody confers such strong neutralizing effects.

They suggest that a cocktail containing both antibodies could provide direct therapeutic benefits for patients with COVID-19.

The finding regarding viral peak epitopes could also help the development of small-molecule antivirals and vaccine candidates to fight the SARS-CoV-2 virus, the researchers added.