Study reveals that proteins taken from shark immune systems can neutralise COVID-19 and its variants

As the deadly coronavirus (COVID-19) pandemic wreaked havoc across the world in the past two years, scientists and researchers are busy developing ways to counter the threat efficiently and curb the spread of the virus in the community. 

Safety measures such as face masks, social distancing, sanitising are still in place in the areas where the cases are rising, owing to new variants and community spread. 

COVID-19 vaccines are effective against the virus but their effect sometimes varies in case of the mutations of the virus, the complexity of vaccination strategies, etc. 

New research, published in Nature Communications, has revealed that antibody-like proteins found in a shark's immune system can also be a counter to the Covid. The proteins could also prevent different variants – such as Delta, Omicron. 

"This study highlights the utility of VNARs as effective therapeutics against coronaviruses and may serve as a critical milestone for nearing a paradigm shift of the greater biologic landscape," abstract of the study read. 

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Aaron LeBeau, a pathologist from the University of Wisconsin-Madison and a co-author of the new study, said in a statement, "These small antibody-like proteins can get into nooks and crannies that human antibodies cannot access."

"They can form these very unique geometries. This allows them to recognize structures in [coronavirus] proteins that our human antibodies cannot," he added. 

The study mentioned that the single-domain Variable New Antigen Receptors (VNARs) from the immune system of sharks are the smallest naturally occurring binding domains found in nature.

As per the study, the ability of the VNARs to neutralise the Covid virus rivalled or exceeded that of full-length immunoglobulins and other single-domain antibodies. 

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Crystallographic analysis of two VNARs found that they recognised separate epitopes on the RBD and had distinctly different mechanisms of virus neutralisation unique to VNARs. 

Structural and biochemical data suggest that VNARs would be effective therapeutic agents against emerging SARS-CoV-2 mutants, including the Delta variant. 

"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," he added.