New Coronavirus Threat from China
A recently identified coronavirus in China has raised concerns about the potential for a new pandemic, according to scientists. This new virus, known as HKU5-CoV-2, is reportedly just one minor mutation away from being able to infect humans and trigger outbreaks.
The worry stems from its close relationship to MERS, which is notably deadly, claiming the lives of up to one-third of those who contract it. There’s also controversy surrounding HKU5, as it was first discovered in bats by scientists associated with the laboratory where there are fears COVID-19 may have originated.
A team from Washington State University conducted a study to understand how this new virus interacts with human cells, which, well, sounds pretty concerning. Professor Michael Letko, who co-led the research, indicated that HKU5 viruses had not been thoroughly studied before, but their findings show how these viruses can effectively infect cells. He mentioned that HKU5 viruses might be just a small step from crossing into humans.
They found that a minor change to the virus’s spike protein could allow it to bind to human ACE2 cells, which are located in various parts of the body, like the throat and nose. This is a bit unsettling.
Researchers collected the HKU5-CoV-2 strain from a select group of bats in southern and eastern China. At the moment, this virus seems to only be circulating among bats, but experts are concerned because the unregulated wildlife trade in China could heighten the risk of spillover events into humans.
In their lab, scientists used gene-editing techniques to design ‘pseudoviruses’ incorporating the HKU5 spike protein. These harmless particles were tested on different cell types, some of which had bat ACE2 while others had human ACE2. The bat cells showed significant reactions, indicating HKU5 can easily infect them. However, human cells didn’t react much unless the virus had specific beneficial mutations for binding to ACE2.
The results lead to worries that if HKU5 were to jump to an intermediate animal, like mink or civets, it could gain mutations that would enable it to infect humans more easily. It’s like a cautionary tale unfolding.
Bureau investigations suggest that COVID-19 likely emerged from a lab leak at the Wuhan Institute of Virology, which was known to be researching dangerous coronaviruses prior to the pandemic.
Another perspective suggests that a wet market with various animals in poor living conditions might have also acted as an intermediate host for this virus before it transferred to humans.
The study, published in Nature Communications, focused on a lesser-known group of coronaviruses called merbecoviruses, which includes HKU5 and MERS-CoV, both of which have significant implications for public health. MERS, for instance, spreads from camels to humans and has a high fatality rate.
To visualize the structure of the virus, researchers employed cryo-electron microscopy, which provided detailed imagery of its spike protein. They observed that crucial parts of this spike protein remained ‘closed’, complicating infection, but it still isn’t an impossibility.
Letko emphasized the importance of monitoring these viruses, especially since they are closely related to MERS. He stated there’s no current evidence of them infecting humans, but the possibility remains, and that’s rather concerning.
Earlier in the year, some researchers in Wuhan reported that at least one strain of HKU5 could already bind to human ACE2 receptors. This would imply it might be capable of infecting human cells without any further evolution.
The ongoing investigation by U.S. researchers now encompasses the entire merbecovirus family rather than focusing solely on one strain—looking into dozens, including multiple HKU5 variants, to gauge their potential to infect human cells. It’s somewhat alarming that Lineage 2 may already be equipped to enter human cells.
Furthermore, this new research indicates other HKU5 virus types could only be a few mutations away from achieving the same capability.
