A virus recently discovered in a Russian bat is similar to the one that caused the Covid-19 pandemic and could also infect humans, a new study finds.
Researchers, including those from Washington State University in the United States, have found that spike proteins from the bat virus, called Khosta-2, can infect human cells and that it is resistant to both antibodies and the serum of individuals vaccinated for. SARS-CoV-2.
They say both Khosta-2 and Covid virus belong to the same sub-category of coronaviruses known as sarbecoviruses.
“Our research further demonstrates that sarbecoviruses circulating in wildlife outside Asia – even in places like western Russia where the Khosta-2 virus was found – also pose a threat to global health and vaccination campaigns. ongoing against Sars-CoV-2, “the scientists wrote in the study, published Thursday in the journal PLOS Pathogens.
Researchers are calling for the development of universal vaccines to protect against sarbecoviruses in general, rather than just known variants of the SARS-CoV-2 virus.
“Unfortunately, many of our current vaccines are designed for specific viruses that we know infect human cells or those that appear to pose the greatest risk of infecting us. But this is an ever-changing list. We need to expand the design of these vaccines to protect them from all sarbecoviruses, “study co-author Michael Letko said in a statement.
Scientists initially discovered the Khosta-1 and Khosta-2 viruses in Russian bats in late 2020, but they thought they were not a threat to humans.
“But when we looked at them more, we were really surprised to find that they could infect human cells. This changes our understanding of these viruses somewhat, where they come from and which regions they affect, “said Dr Letko.
While Khosta-1 posed a low risk to humans, the researchers say Khosta-2 demonstrated some troubling traits.
They found that it can use its spike protein to infect cells by binding to a receptor protein, called angiotensin-converting enzyme 2 (ACE2), found in human cells.
It is the same ACE2 protein that the Covid-19 virus uses as a gateway to enter and infect human cells.
When scientists evaluated whether current Covid vaccines can protect against the new virus using serum derived from human populations vaccinated for Covid-19, they found that Khosta-2 was not neutralized.
The researchers also tested the serum of people who had been infected with the omcron variant against Khosta-2, but even these antibodies were ineffective.
Although the new virus lacks some genes believed to be involved in the pathogenesis of humans, they say there is a risk that Khosta-2 will recombine with a second virus such as Sars-CoV-2.
“When you see Sars-2 it has this ability to spill over to humans and wildlife, and then there are other viruses like Khosta-2 waiting in those animals with these properties that we don’t really want them to have, set this scenario where you continue. to roll the dice until they combine to create a potentially riskier virus, “said Dr. Letko.