New York, April 18: Scientists have revealed how a highly infectious variant of SARS-CoV-2 virus binds to host but succumbs to antibodies later, a discovery that could help in the development of more potent Covid vaccines.
Large-scale supercomputer simulations at the atomic level showed that the dominant "G form" variant of the Covid-19 causing virus is more infectious partly because of its greater ability to readily bind to its target host receptor in the body, compared to other variants.
The results from a Los Alamos National Laboratory-led team in the US illuminate the mechanism of both infection by the G form and antibody resistance against it.
"We found that the interactions among the basic building blocks of the Spike protein becomes more symmetrical in the G form, and that gives it more opportunities to bind to the receptors in the host -- in us," said Gnana Gnanakaran, corresponding author of the paper published in Science Advances.
"At the same time, that means antibodies can more easily neutralise it. In essence, the variant puts its head up to bind to the receptor, which gives antibodies the chance to attack it."
Researchers knew that the variant, also known as D614G, was more infectious and could be neutralised by antibodies, but they didn't know how.
Simulating more than a million individual atoms and requiring about 24 million CPU hours of supercomputer time, the new work provides molecular-level detail about the behaviour of this variant's Spike.
Current vaccines for SARS-CoV-2, the virus that causes Covid-19, are based on the original D614 form of the virus.
This new understanding of the G variant -- the most extensive supercomputer simulations of the G form at the atomic level -- could mean it offers a backbone for future vaccines.