Sharks may be able to protect us from coronavirus

Nurse sharks gliding around a tank at the University of Wisconsin-madison may hold the secret to an unusual, previously unexamined treatment for COVID-19, according to a new study published in December in the journal Nature Communications.

Antibodies derived from the immune systems of sharks proved effective against the new coronavirus, including the Delta variant, in lab experiments using human lung and embryonic kidney cells.

In a lab dish, the shark antibodies block the connection between the virus’ Spike protein and the ACE2 receptor on human cells – the critical link that provides the virus with a gateway into our cells.

“They’ve never been tested in people,” cautioned Aaron M. Lebeau, a cancer biologist at the University of Wisconsin School of Medicine and Public Health who helped lead the new study.

Although shark antibodies are likely years away from use in people, the idea isn’t as strange as it might sound.

“It’s possible that you could inject them into humans and our immune system would not recognize them as being foreign,” Lebeau said, explaining that shark antibodies would not be rejected because they are similar in some respects to human antibodies.

Despite the development of vaccines against COVID-19, the search for treatments remains crucial. Even though the vaccines have proven highly effective, they don’t provide 100% protection for everyone, as evidenced by breakthrough infections.

The most recent numbers from the Centers for Disease Control and Prevention show that about 91 of every 100,000 fully vaccinated people still get COVID-19. The infection rate for unvaccinated people is five times higher – 452 of every 100,000 people.

So far the U.S. Food and Drug Administration has given emergency use authorization to two human antibody treatments for COVID-19. One is known as Bamlanivimab. The other is Regeneron’s cocktail of laboratory-produced antibodies, one of the eight drugs used to treat then-president Donald Trump when he got COVID-19 in 2020.

In the lab, the shark antibodies proved “as good or better” than the two human antibody products and they are just 10% of the size, so “you get more bang for the buck,” Lebeau said.

Lebeau came to work at UW in April after seven years at the University of Minnesota. The university agreed to build a tank large enough to house adult nurse sharks for his research. Nurse sharks can reach a length of up to 10 feet and weigh more than 700 pounds.

UW is not disclosing the number of nurse sharks it has or the tank’s location on campus, but Lebeau said, “We’re now the premier shark antibody lab in the world.”

Sharks have been around close to 500 million years and have developed a unique immune system. Their antibodies are very small and have a distinctive shape, allowing them to tightly pack, and therefore block, the part of the virus that must grab onto human cells.

Only a few other living creatures – camels, llamas and alpacas – are known to have similar antibodies.

In addition, the shark antibodies are hardy.

“You can boil them and they still work. They’re pretty much indestructible. That’s one very exciting selling point to shark antibodies,” said Lebeau, who collaborated on the new study with scientists at the University of Minnesota and Elasmogen Ltd, a Scottish biomedical company.

“We think they’re the next big thing. This is the first paper to show their effectiveness against an infectious disease.”

In the lab, the shark antibodies proved “as good or better” than the two human antibody products and they are just 10% of the size.