A newly discovered bat coronavirus, HKU5-CoV-2, has raised concerns due to its ability to infect human cells, much like the virus that caused the COVID-19 pandemic.
According to the South China Morning Post (SCMP), the virus was identified by a team of virologists led by Shi Zhengli, a prominent scientist from the Wuhan Institute of Virology, often referred to as "Batwoman" for her extensive work on coronaviruses. The Wuhan Institute has previously been at the centre of the controversial lab leak theory regarding COVID-19, which China has repeatedly denied.
Researchers found that HKU5-CoV-2 shares similarities with SARS-CoV-2, the virus behind COVID-19, as it can bind to human ACE2 receptors — the same mechanism that allowed COVID-19 to infect humans, SCMP reported.
What is HKU5-CoV-2?
HKU5-CoV-2 belongs to the merbecovirus subgenus, which also includes the virus responsible for Middle East Respiratory Syndrome (MERS). Scientists discovered that this virus can attach to human ACE2, much like SARS-CoV-2 and NL63 (a common cold virus).
During laboratory tests, researchers observed that HKU5-CoV-2 successfully infected human cell cultures and mini-human organ models.
"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, as reported by Newsweek. However, it emphasised that the virus’s potential for human transmission "remains to be investigated."
The research team further noted: "Structural and functional analyses indicate that HKU5-CoV-2 has a better adaptation to human ACE2 than lineage 1 HKU5-CoV."
They concluded: "Authentic HKU5-CoV-2 infected human ACE2-expressing cell lines and human respiratory and enteric organoids. This study reveals a distinct lineage of HKU5-CoVs in bats that efficiently use human ACE2 and underscores their potential zoonotic risk."
Could this lead to another pandemic?
When asked about the risk of a new pandemic, Dr Michael Osterholm, an infectious disease expert at the University of Minnesota, dismissed such concerns as exaggerations. He pointed out that global immunity to SARS-related viruses is much higher now than it was in 2019, potentially lowering the risk.
Moreover, the study itself clarified that HKU5-CoV-2 has a significantly lower binding affinity for human ACE2 than SARS-CoV-2. Several other factors make it suboptimal for human transmission. The researchers stated that the "risk of emergence in human populations should not be exaggerated."
While the discovery highlights the ongoing potential for animal-to-human virus spillover, it remains unclear whether HKU5-CoV-2 poses a significant threat to human health.
