Danger from HKU5-CoV-2: Could the new coronavirus trigger a pandemic?

Scientists in Wuhan discover a new coronavirus in bats. What is worrying is that the pathogen uses the same cell surface protein as SARS-CoV-2. Experts warn against panic, but emphasize the need for vigilance. How dangerous is HKU5-CoV-2 really?

A new study from China is causing a stir because it brings back bad memories: Scientists at the Wuhan Institute of Virology have discovered a new coronavirus called HKU5-CoV-2 in bats. What is particularly worrying is that the virus uses the same cell surface protein to penetrate human cells. This ACE2 receptor played a crucial role in the spread of the virus during the pandemic. The study authors now fear that HKU5-CoV-2 could one day also jump to humans. But how great is the danger really? Could the virus trigger a new pandemic?

Laboratory analyses showed that HKU5-CoV-2 is related to the MERS virus (Middle East Respiratory Syndrome) - both pathogens belong to the subgenus of Merbecoviruses. The severe respiratory disease MERS first appeared in Saudi Arabia in 2012 and has a high mortality rate. According to the World Health Organization, up to 36 percent of cases are fatal. Although HKU5-CoV-2 is genetically related to MERS, it is still unclear whether it can also cause serious diseases in humans.

One thing is certain, however: "Bat merbecoviruses that are phylogenetically related to MERS-CoV pose a high risk of jumping to humans, either through direct transmission or through intermediate hosts," the study states. Despite its potential to infect human cells, the research team also emphasizes that HKU5-CoV-2 does not appear to be as efficient as SARS-CoV-2 in transmitting to humans. Therefore, in their study, they conclude that while HKU5-CoV-2 "efficiently utilizes human ACE2," the actual risk to the human population "should not be exaggerated."

No reason to panic

Michael Osterholm also believes that the danger posed by HKU5-CoV-2 is currently low. The infectious disease expert at the University of Minnesota warns against panic-mongering. He told the Reuters news agency that people have a high level of immunity to similar SARS viruses compared to 2019.

Meanwhile, David Heymann of the London School of Hygiene & Tropical Medicine (LSHTM) urged prudence, but also vigilance. "Newly identified viruses in animals, such as HKU5-CoV-2, remind us that we must remain vigilant and inform people about potential disease threats, without suggesting that every new virus could lead to a new pandemic in humans," he said in a statement . "It is not possible to predict when and where a new virus or mutation of an existing virus will emerge, or how harmful it might be to humans."

The scientists in Wuhan now want to investigate what role intermediate hosts could play in the transmission of HKU5-CoV-2 to humans. Bats in particular were the crucial link in previous coronaviruses. SARS-CoV-1, which triggered the SARS outbreak in 2003, probably jumped from bats to civet cats before infecting humans. MERS-CoV probably jumped from bats to camels and then to humans.

Viruses are constantly evolving

Even if HKU5-CoV-2 does not currently pose a major threat, experts emphasize the importance of continuous monitoring. Viruses are constantly evolving - what seems relatively harmless today could become more contagious and dangerous in the future. HKU5-CoV-2 is not "new or newly discovered" in itself, virologist Timo Ulrichs told "Focus". Its existence has been known since 2006. "But it has now been proven that the virus has changed and can also recognize human structures with its surface molecules."

If people do become infected, there are already possible treatment methods thanks to the corona pandemic. Monoclonal antibodies and antiviral agents that have been used to treat COVID-19 could also be effective against HKU5-CoV-2, the study says. Drugs such as Remdesivir and Nirmatrelvir, among others, appear to be effective against the virus, at least in the test tube.

Most experts agree that a new pandemic could occur at some point. Zoonoses, i.e. infectious diseases that can be transmitted from animals to humans, are particularly considered potential triggers. "That's why it's important to invest more in zoonosis research so that we can better prepare for a possible new pandemic with a pathogen from the animal reservoir," says virologist Ulrichs.

"It is also important that we have secure laboratories with strict and well-controlled biosecurity measures," emphasizes infectious disease specialist Heymann. The Wuhan Institute of Virology was at the center of a controversy over theories that COVID-19 was the result of a laboratory accident. A claim that China consistently denies to this day. Most experts assume that the virus jumped from animals to humans at a wildlife market. But regardless of its origin, the pandemic has shown how important it is to detect and combat a new pathogen early.