A newly discovered coronavirus strain in China, dubbed HKU5-CoV-2, is raising concerns among global health experts for its potential to trigger another pandemic if it mutates further.
In a recent study published in Nature Communications, scientists from Washington State University analyzed HKU5-CoV-2, a little-known virus in the merbecovirus group that includes the deadly MERS virus. The team found that the virus can already infect and replicate within human airway and intestinal cells—though not as efficiently as SARS-CoV-2, the virus responsible for Covid-19.
“What we also found is HKU5 viruses may be only a small step away from being able to spill over into humans,” warned virologist Professor Michael Letko, who co-led the study.
Their research revealed that with minor changes in its spike protein, HKU5-CoV-2 could bind to the human ACE2 receptor—found in the throat, nose, and mouth—giving it a possible entry route into the human body.
The variant was first identified in bats in China in February 2025 and has since caught the attention of scientists due to its ability to infect a broader range of animals than previous coronaviruses.
Though there is no confirmed case of human infection yet, the virus’s resemblance to MERS, which has a fatality rate of around 35%, is cause for serious concern. According to the World Health Organization, MERS has killed 858 people across 27 countries since 2012, often transmitted from camels to humans.
“This virus group hasn’t been studied as much,” Letko added. “But what we’re seeing now suggests it needs close monitoring.”
While experts are urging caution and not panic, they stress the importance of continued surveillance to detect early signs of spillover from animals to humans—a lesson hard learned from the origins of Covid-19.
