Researchers have found that shark antibodies can prevent the virus that causes Covid-19, its variants, and related coronaviruses from infecting human cells.
Small, antibody-like proteins known as VNARs (Variable New Antigen Receptors) are derived from the immune systems of sharks, and appear to be extremely potent in preventing Covid-19, as well as its variants, and related coronaviruses from infecting human cells.
The shark proteins are ten times smaller than human antibodies and can bind to infectious proteins in unique ways that bolster their ability to stop infection. "These small antibody-like proteins can get into nooks and crannies that human antibodies cannot access,” said study co-leader Aaron LeBeau, a professor of pathology at the University of Wisconsin–Madison.
In one of the experiments, such a protein neutralized WIV1-CoV—a coronavirus present in the bodies of bats capable of infecting humans. In turn, in a pool of synthetic VNARs developed by Elasmogen, researchers found three SARS-CoV-2 neutralizing proteins. The same proteins were also effective against the virus that caused SARS in 2003.
The new VNARs will not be immediately available as a treatment in people, but they can help prepare for future coronavirus outbreaks.
“The big issue is there are a number of coronaviruses that are poised for emergence in humans,” said LeBeau. “What we’re doing is preparing an arsenal of shark VNAR therapeutics that could be used down the road for future SARS outbreaks. It’s a kind of insurance against the future.”
The shark VNARs were able to neutralize WIV1-CoV, a coronavirus that is capable of infecting human cells but currently circulates only in bats, where SARS-CoV-2, the virus that causes Covid-19, likely originated.
According to the researchers, possible future treatments are likely to take the form of a cocktail of different shark proteins, to maximize their effectiveness against a range of different and mutating viruses. Their application may be even wider. Scientists are already studying the potential of shark proteins in the diagnosis and treatment of cancer.