When SARS-CoV-2 – the virus behind COVID-19 – appeared in China and quickly stopped the entire world, then-President Donald Trump liked to call it the “Chinese virus.”
Fast forward two and a half years, and US scientists warn that a newly discovered virus stored by Russian horseshoe bat bats is also capable of infecting humans and avoiding COVID-19 antibodies and vaccines.
A bat virus called Khosta-2 is known as sarbecovirus – the same subcategory of coronaviruses as SARS-CoV-2 – and exhibits “worrying traits,” according to a new study published in the journal PLoS Pathogens.
A team led by researchers at the Paul G. Allen School for Global Health at Washington State University (WSU) found that Khosta-2 could use its spiny proteins to infect human cells, much like SARS-CoV-2 does.
“Our research further shows that sarbecoviruses circulating in wild animals outside of Asia – even in places like Western Russia where the Khosta-2 virus has been found – also pose a threat to global health and ongoing SARS-CoV-2 vaccination campaigns.” – Michael Letko , WSU virologist and corresponding author of the study, said in a statement.
He said this discovery underscores the need to develop new vaccines that not only target known SARS-CoV-2 variants such as Omicron, but that protect against all sarbecoviruses.
“Strange Russian Viruses”
Of the hundreds of sarbecoviruses discovered in recent years, most have been found in Asian bats and are unable to infect human cells.
The Khosta-1 and Khosta-2 viruses were discovered in bats near Russia’s Sochi National Park in 2020 and, according to the authors of the study, initially did not seem to pose a threat to humans.
“Genetically, these strange Russian viruses looked like some of the others that had been discovered elsewhere in the world, but since they didn’t look like SARS-CoV-2, no one thought they were something to get too excited about,” Letko said.
“But when we looked at them closely, we were really surprised to discover that they could infect human cells. This changes our understanding of these viruses a little, where they come from and which regions they affect. ‘
Letko and his colleagues determined that the Khosta-1 posed a low risk to humans, but the Khosta-2 was more disturbing.
In particular, like SARS-CoV-2, Khosta-2 can use its spike protein to infect cells by attaching to a receptor protein called angiotensin converting enzyme 2 (ACE2) that is found in human cells.
Next, researchers wanted to find out if the virus could avoid the immunity offered by previous coronavirus infections or the COVID-19 vaccine.
Using serum from people vaccinated against COVID-19, the team found that Khosta-2 had not been neutralized by current vaccines.
They also tested serum from people infected with the Omicron variant, but again the antibodies were ineffective there.
Fortunately, the authors write that the new virus lacks some genetic traits that are believed to ‘antagonize’ the immune system and contribute to disease in humans – but there is a risk that Khosta-2 could wreak havoc by recombining with a second virus such as SARS -CoV-2.
“When you see SARS-2 has this ability to spread back from humans to wild animals, then there are other viruses like Khosta-2 waiting for these animals with these properties we really don’t want them to have,” this sets up a scenario where you roll the dice until they combine to create a potentially riskier virus, ”Letko said.