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New Vaccine Blocks New Coronavirus and Variants in Animal Study | India News


NEW DELHI: A new candidate vaccine has been shown to be effective in protecting monkeys and mice from the new coronavirus and its variants that first emerged in the UK, South Africa and Brazil, as well as related bat coronaviruses that could cause the next pandemic, according to a study.
The finding, published in the journal Nature, is highly relevant to humans, the researchers said.
The pan-coronavirus vaccine triggers neutralizing antibodies through a nanoparticle made up of the coronavirus part.
This part allows the vaccine to bind to cell receptors in the body and is formulated with a chemical booster called an adjuvant, the researchers said.
“We began this work last spring with the understanding that, like all viruses, mutations would occur in the SARS-CoV-2 virus, which causes COVID-19,” said study lead author Barton F. Haynes, from the Institute for Human Vaccines at Duke University. In the USA.
“The new approach not only provided protection against SARS-CoV-2, but the vaccine-induced antibodies also neutralized worrisome variants that originated in the UK, South Africa and Brazil,” Haynes said.
The induced antibodies reacted with a fairly large panel of coronaviruses, he added.
Haynes and his colleagues built on earlier studies of SARS, the respiratory disease caused by a coronavirus called SARS-CoV-1.
They found that a person who had been infected with SARS developed antibodies capable of neutralizing multiple coronaviruses, suggesting that a pan-coronavirus could be possible.
The researchers noted that the Achilles heel of coronaviruses is their receptor-binding domain, located at the peak that binds viruses to receptors on human cells.
While this binding site allows it to enter the body and cause an infection, it can also be attacked by antibodies, they said.
The team identified a particular receptor-binding domain site that is present in SARS-CoV-2, its circulating variants, and SARS-related bat viruses that makes them highly vulnerable to cross-neutralizing antibodies.
The team then designed a nanoparticle that shows this vulnerable spot.
The nanoparticle is combined with a small molecule adjuvant formulated with alum that stimulates the body’s immune response, according to the researchers.
In tests of its effect on monkeys, the nanoparticle vaccine blocked Covid-19 infection by 100 percent, they said.
The researchers observed that the new vaccine also caused significantly higher neutralization levels in animals than current vaccine platforms or natural infection in humans.
“Basically what we’ve done is take multiple copies of a small part of the coronavirus to make the body’s immune system respond to it in a more intense way,” said lead study author Kevin Saunders.
“We found that not only did this increase the body’s ability to inhibit the virus from causing infection, but it also targets this site of cross-reactive vulnerability in the spike protein more often,” Saunders added.
The team said that is why this vaccine is effective against SARS-CoV-1, SARS-CoV-2, and at least four of their common variants, in addition to other animal coronaviruses.

Times of India