Researchers have discovered a virus that can enter human cells in a similar way to the virus that causes COVID-19. But the germ — HKU5-CoV-2 — doesn’t enter cells as effectively, so experts caution the findings shouldn’t be “overblown.”
Scientists at the Wuhan Institute of Virology in China described the virus and potential treatments for infections in the journal Cell this week.
What is HKU5-CoV-2?
HKU5-CoV-2 is a virus found in bats. It’s a type of coronavirus, a large group of germs that can affect mammals and birds. Some have passed from animals to humans, like SARS-CoV-2, which causes COVID-19. Some coronaviruses cause mild symptoms in humans, while others can be lethal.
Scientists study viruses like HKU5-CoV-2 to find out how they work and how readily they might pass to humans. The Wuhan Institute researchers tested the newly-discovered germ in test tubes and models of the human gut and airways to investigate its transmission potential.
They found the virus’s spike protein was able to bind with the membrane of human cells via a receptor enzyme that sits on their surface. This protein has a feature called a “furin cleavage site” that helps it latch on to the receptor enzyme.
Is HKU5-CoV-2 A Threat To Humans?
This potential transmission pathway is similar to that of the highly-contagious SARS-CoV-2. But although it was better adapted to human cells than certain other similar viruses, HKU5-CoV-2 did not infect human cells as readily as SARS-CoV-2. In fact, it was significantly worse at binding to human cells, among other limitations.
Because of this, scientists have urged caution over the results. The researchers themselves wrote in their study that the “risk of emergence in human populations should not be exaggerated.”
University of Minnesota infectious disease expert Dr. Michael Osterholm told Reuters the reaction to the research was “overblown.” He said it was also possible that increased immunity to similar viruses could help protect the public from another pandemic.
Despite these calls for caution, the news appears to have boosted shares in the manufacturers behind vaccines for COVID-19. Shares of Pfizer, Moderna and Novovax rose on Friday following the news, according to Bloomberg.
How Might HKU5-CoV-2 Be Treated?
Should a bat virus like HKU5-CoV-2 infect a human, the researchers said monoclonal antibodies and antiviral drugs might help treat it.
Antiviral drugs are designed to stop the spread of virus around the body, potentially easing symptoms and shortening illness. They’re used to treat a range of illnesses, including flu and COVID-19.
Monoclonal antibodies are proteins made in labs to target a wide range of illnesses, including cancer. They have been tailored to the spike protein of SARS-CoV-2, for example, to try and prevent it from infecting human cells — a treatment that’s especially important for people with weak immune systems who may not gain strong protection from vaccines.
They can be highly effective treatments, but their efficacy for COVID-19 varies depending on the variant a patient contracts. So scientists had to develop new monoclonal antibody treatments quickly to try and keep up with the mutating virus.
