A newly discovered bat coronavirus, HKU5-CoV-2, can enter human cells using the same ACE2 receptor as SARS-CoV-2, the virus behind COVID-19. While this raises concerns about potential human transmission, scientists stress that HKU5-CoV-2 currently poses a lower threat, according to a study.
The virus shares a crucial trait with SARS-CoV-2 — the furin cleavage site — which aids cell entry. However, researchers found that HKU5-CoV-2 does not infect human cells as efficiently. Lab tests showed that while the virus could infect human cell models, including intestinal and airway cells, it has significantly weaker binding to ACE2 than SARS-CoV-2 and lacks key adaptations for easy human transmission.
The study also identified monoclonal antibodies and antiviral drugs that were effective against the virus in lab settings. However, scientists caution against exaggerating the threat. “The risk of emergence in human populations should not be exaggerated,” the researchers concluded.
How dangerous is HKU5-CoV-2
Despite its ability to infect human cells, HKU5-CoV-2 does not appear to spread as easily among humans as SARS-CoV-2. Dr. Michael Osterholm, an infectious disease expert at the University of Minnesota, called reactions to the study “overblown,” noting that global immunity to SARS-like viruses is now higher than in 2019, reducing the likelihood of a new pandemic.
The virus belongs to the merbecovirus subgenus, which includes the MERS-CoV virus responsible for Middle East respiratory syndrome (MERS). MERS, first detected in 2012, spreads from camels to humans and has a high fatality rate. Though HKU5-CoV-2 is genetically related to MERS, its potential to cause severe illness in humans remains unclear.
“Bat merbecoviruses, which are phylogenetically related to MERS-CoV, pose a high risk of spillover to humans, either through direct transmission or facilitated by intermediate hosts,” the study stated
Could HKU5-CoV-2 trigger another pandemic
While some worry that HKU5-CoV-2 could spark another global health crisis, there is no evidence yet that it can spread between humans. In past outbreaks, coronaviruses have jumped to humans through intermediate hosts — SARS-CoV-1, which caused the 2003 SARS outbreak, likely spread from bats to civet cats before infecting humans, while MERS-CoV moved from bats to camels before reaching people. Scientists are now investigating whether HKU5-CoV-2 follows a similar pattern.
The discovery of HKU5-CoV-2 comes as the world continues to deal with the long-term impact of COVID-19, which has caused more than 7 million recorded deaths — though the true toll may exceed 20 million.
