Like other viruses, SARS-CoV-2 features a spike protein, which helps it penetrate and infect previously healthy cells.
But while the spike protein typically plays a role in infection, scientists can also use it in vaccines, to “train” a person’s immune system to recognize and fight the virus.
Recently, a team of investigators from the University of Texas at Austin has created a version of the SARS-CoV-2 spike protein that, they argue, might help bring vaccines to more people faster.
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According to senior author Jason McLellan, associate professor in the Department of Molecular Biosciences:
“Depending on the type of vaccine, this improved version of the protein could reduce the size of each dose or speed up vaccine production. Either way, it could mean more patients have access to vaccines faster.”
McLellan and his colleagues present their research and describe the innovative protein, which they have named HexaPro, in a study paper featured in the journal Science.
The researchers had previously described the structure of the SARS-CoV-2 spike proteins.
For their study, the scientists drew on previous research around creating more stable spike proteins for use in vaccines against MERS-CoV, the coronavirus that causes MERS.
The team initially outlined as many as 100 modifications of the spike protein that, they believed, might generate the final, stabilized protein.
When they inserted each of the 100 modified versions of the spike protein into different human cell cultures, they identified the top 26 most stable ones.
Eventually, the researchers combined four of these modifications to form the final stabilized spike protein HexaPro. When they injected this new spike protein into human cells, they found that it had a tenfold higher protein expression than the original.
The fact that HexaPro is more stable than the spike protein they originally described should render its storage and transportation easier, the researchers explain.
The researchers also believe that it is more resistant to heat stress and keeps its shape when stored at room temperature, or if frozen and thawed repeatedly.
In theory, this should make it a more desirable candidate for inclusion in experimental vaccines against the new coronavirus, as its stability could help fast-track vaccine production.
“Four billion people living in developing countries will need access to a vaccine, as all of us will,” emphasizes McLellan.
Moreover, according to the scientists, HexaPro might also be valuable in antibody tests. They think it might help specialists identify antibodies to SARS-CoV-2 in the blood, which would show whether a person has previously contracted the virus.
The researchers have benefited from a grant from the Bill & Melinda Gates Foundation.
At this point, Sino Biological — a biotechnology company based in Beijing, China — holds a non-exclusive license to manufacture and resell HexaPro.
The scientists who identified HexaPro have also now filed a U.S. patent application for the modified protein.
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