Another pandemic looming? New bat coronavirus capable of human transmission discovered in China

Security personnel keep watch outside Wuhan Institute of Virology during the visit by the World Health Organization (WHO) team. (Image: Reuters)

Chinese researchers have discovered a new bat coronavirus that poses potential risks of animal-to-human transmission, sparking concerns of future spillover events, like Covid-19.

The virus, identified as HKU5-CoV-2, belongs to the merbecovirus subgenus, which includes the Mers virus. This newly isolated strain can bind to the ACE2 receptor in human cells, the same pathway used by the Covid-19 virus, according to the study cited by news agency Reuters.

However, the virus does not enter human cells as readily as SARS-CoV-2 does, the Chinese researchers reported in the journal Cell, noting some of its limitations.

According to the South China Morning Post (SCMP), the new virus was found by a team of virologists led by Shi Zhengli, the famed scientist known as "Batwoman" for her lifetime work in coronaviruses, especially at the Wuhan Institute, which has been at the centre of the theory suggesting COVID-19 came from a lab leak - something China has denied repeatedly.

What is HKU5-CoV-2?

A new virus called HKU5-CoV-2 has been discovered in bats in China. Despite the potential risk of infecting humans, the researchers said more details on animal-to-human transmission are yet to be investigated.

While there are hundreds of coronaviruses in the wild, only a few can infect humans.

HKU5-CoV-2, that traces its lineage from the HKU5 coronavirus first identified in the Japanese pipistrelle bat in Hong Kong, comes from the merbecovirus subgenus, which also includes the virus that causes Middle East Respiratory Syndrome (Mers).

The scientists said that like SARS-CoV-2, the bat virus HKU5-CoV-2 contains a feature known as the furin cleavage site that helps it to enter cells via the ACE2 receptor protein on cell surfaces.

In lab experiments, HKU5-CoV-2 infected human cells with high ACE2 levels in test tubes and in models of human intestines and airways. In further experiments, the researchers identified monoclonal antibodies and antiviral drugs that target the bat virus, Reuters reported.

The study also noted that the virus has significantly less binding affinity to human ACE2 than SARS-CoV-2, and other suboptimal factors for human adaptation suggest the "risk of emergence in human populations should not be exaggerated".

Could we be facing another pandemic?

When asked about concerns raised by the report of another pandemic resulting from this new virus, Dr Michael Osterholm, an infectious disease expert at the University of Minnesota, called the reaction to the study "overblown." He said there is a lot of immunity in the population to similar SARS viruses compared with 2019, which may reduce the pandemic risk, as reported by Reuters.

Notably, the study itself has stated that the virus has significantly less binding affinity to human ACE2 than SARS-CoV-2, and other suboptimal factors for human adaptation suggest the "risk of emergence in human populations should not be exaggerated".

(With inputs from Reuters)