A potentially mutating bat virus has some scientists worried about the next pandemic

Five years removed from the onset of Covid-19's global sweep, research into another subset of the coronavirus has scientists worried about another possible pandemic. This virus originated in bats, as most scientists believe Covid-19 did, and for now, the research has stressed that it is unable to do much damage to humans. But a potential viral mutation may change that.

What is the virus?

The pathogen in question is HKU5, which is naturally found in the Japanese house bat. HKU5 is a subgroup of the merbecovirus, which is itself a subcategory of the coronavirus that causes diseases like Middle East Respiratory Syndrome (MERS). A recent study published in the journal Nature Communications examined a "scalable approach to assess novel merbecovirus cell entry across the entire merbecovirus subgenus," said the study's publication.

This marks a ramping up of research into HKU5, and what type of threat viruses like it could pose. In the "past two decades, scientists have cataloged the genetic sequences of thousands of viruses in wild animals," but in "most cases, little is known about whether these viruses pose a threat to humans," said the University of Washington, which helped spearhead the study.

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Could HKU5 cause another pandemic?

While HKU5 in its current form is unlikely to infect humans, scientists say this could change if it were to mutate. Even though most merbecoviruses are "unlikely to have the capacity to infect humans, the HKU5 subgroup can," said Newsweek. The study found that HKU5 is able to "latch onto the ACE2 receptor on target cells." This is the same method that the coronavirus strain identified in 2019 uses to transmit Covid-19.

At the moment, HKU5 viruses are "only able to adequately exploit the ACE2 receptor in bats — and are far less proficient at latching onto those found on human cells," said Newsweek. Still, scientists have already identified potential mutations that "might allow the viruses to bind to the ACE2 receptors in other species, including humans."

HKU5 is similar to the type of merbecovirus that has caused a MERS outbreak since 2012, so there is legitimate cause for concern. HKU5 "may be only a small step away from being able to spill over into humans," Michael Letko, a virologist at Washington State University's College of Veterinary Medicine and author of the study, said in the university's press release.

While there is "no evidence they've crossed into people yet, the potential is there — and that makes them worth watching," Letko said of these viruses. This is why the study was "offering insights into mutations and potential treatments," and this "research highlights the importance of monitoring these viruses closely," said KAYU-TV Spokane.

Other researchers have downplayed the idea that HKU5 could ever make its way into humans. Chinese scientists first identified the strain in early 2025, and "there is no reason to believe it currently poses a concern to public health," a spokesperson for the U.S. Centers for Disease Control and Prevention told CNN at the time. Even the "researchers themselves point out that this should not cause panic," Dr. Amira Roess, a global health professor at George Mason University, said to the outlet. Research "helps us understand what happens in the event that this does spill over and pose a risk. It's good to get ahead of that."