Mutations Help Epsilon Coronavirus Variant Evade Vaccine Immunity: Study

3 mutations in SARS-CoV-2 variant Epsilon spike protein help it escape vaccines

Washington:

Three mutations in the spike protein of the SARS-CoV-2 variant Epsilon help the virus escape the protection offered by current vaccines or previous infection with COVID-19, according to one study.

The mutations also provide the worrisome variant named CAL.20C with a way to totally evade specific monoclonal or lab-made antibodies used in clinics and reduce the effectiveness of antibodies in the plasma of vaccinated people, the researchers said.

The team, led by researchers at the University of Washington in the United States, visualized the mechanism of infection of the variant to see what is different from the original configuration of the coronavirus and what the implications of these are. changes.

The discovery, published in the journal Science on July 1, shows that the Epsilon variant “relies on an indirect and unusual neutralization-evasion strategy.”

Neutralizing antibodies are an important specific defense against viral invaders.

Molecular clock analysis shows that the precursor to the Epsilon variant appeared in May of last year in California.

By the summer of 2020, it had diverged into its B.1.427 / B.1.429 lineages and had spread across the United States.

The variant has been reported in at least 34 other countries since then.

The researchers tested the resilience against the Epsilon variant of the plasma of people exposed to the virus, as well as people who were vaccinated.

The neutralizing potential of plasma against the worrying Epsilon variant was reduced by about 2 to 3.5 times, they said.

Like the original SARS-CoV-2 virus identified in Wuhan, China in December 2019, the variant infects cells through its advanced glycoprotein – the structure that crowns the surface of the virus and helps infect human cells. .

The researchers found that Epsilon mutations were responsible for rearrangements in critical areas of the peak glycoprotein.

Visualizing these mutations helps explain why the antibodies had difficulty binding to the spike protein, the researchers said.

One of three mutations in the Epsilon variant affected the receptor binding domain on the spike glycoprotein, they said.

This mutation reduced the neutralizing activity of 14 of 34 neutralizing antibodies specific to this domain, including those at the clinical stage.

The other two of the three variant mutations affected the N-terminal domain – the start of the spike protein.

The mutations also resulted in a complete loss of neutralization of 10 of the 10 antibodies tested specific to the N-terminal domain in the spike protein, the researchers added.

(Except for the title, this story was not edited by NDTV staff and is posted from a syndicated feed.)