New vaccine blocks novel coronavirus
A new vaccine candidate has proven effective in protecting monkeys and mice from the novel coronavirus and its variants that first emerged in the UK, South Africa and Brazil, as well as related bat coronaviruses that could potentially 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 neutralising antibodies via a nanoparticle composed of the coronavirus part.
- This part allows the vaccine to bind to the body's cell receptors, 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 senior author Barton F. Haynes, from Duke University Human Vaccine Institute in the US.
- The new approach not only provided protection against SARS-CoV-2, but the antibodies induced by the vaccine also neutralised variants of concern that originated in the United Kingdom, South Africa and Brazil.
- The induced antibodies reacted with quite a large panel of coronaviruses.
- The researchers noted that the Achilles heel for the coronaviruses is their receptor-binding domain, located on the spike that links the viruses to receptors in human cells.
- The team identified one particular receptor-binding domain site that is present on SARS-CoV-2, its circulating variants and SARS-related bat viruses that makes them highly vulnerable to cross-neutralizing antibodies.
- The nanoparticle is combined with a small molecule adjuvant formulated with alum that boosts the body's immune response. In tests of its effect on monkeys, the nanoparticle vaccine blocked COVID-19 infection by 100 per cent.