HKU5-CoV-2: Scientists Discover New Bat Coronavirus in China Similar to SARS-CoV-2

Hong Kong: A newly identified bat coronavirus, HKU5-CoV-2, has been found to use the same cell entry mechanism as SARS-CoV-2, the virus responsible for COVID-19. The discovery has raised concerns about its potential to infect humans, though scientists emphasize that it does not currently pose a significant threat.

Reuters recently reported on the study, highlighting that while HKU5-CoV-2 shares structural similarities with SARS-CoV-2, it does not infect human cells as efficiently, limiting its potential for human transmission. However, researchers stress the importance of continued observation.

What is HKU5-CoV-2?

HKU5-CoV-2 is a newly identified bat coronavirus found in Hong Kong. It has the ability to attach to ACE2 receptors in human cells, similar to SARS-CoV-2. Although it has not yet been detected in humans, researchers say it warrants close monitoring.

Study Findings and Concerns

The study found that HKU5-CoV-2 contains a key structural feature known as the furin cleavage site, which facilitates entry through the ACE2 receptor protein on cell surfaces.

Laboratory experiments demonstrated that HKU5-CoV-2 successfully infected human cells with high ACE2 expression, including test tube models of human intestines and airways. Researchers also identified monoclonal antibodies and antiviral drugs that could potentially target the virus.

Since HKU5-CoV-2 uses the same cellular entry mechanism as SARS-CoV-2, experts have expressed concerns about its potential to jump to humans. However, they note that its ability to bind to human cells is significantly weaker than that of SARS-CoV-2, making widespread human transmission less likely.

Pandemic Risk and Expert Caution

Experts suggest that HKU5-CoV-2 is unlikely to spread as rapidly as SARS-CoV-2. Dr. Michael Osterholm, an infectious disease expert at the University of Minnesota, described the reaction to the study as "overblown."

He noted that population-wide immunity to similar SARS viruses has increased since 2019, which could lower the risk of an outbreak.

The study itself acknowledged that HKU5-CoV-2 has significantly weaker binding affinity to human ACE2 compared to SARS-CoV-2. Other factors also make it suboptimal for human adaptation, leading researchers to conclude that "the risk of emergence in human populations should not be exaggerated."