But even as politicians and health authorities grapple with how, if at all, continue to address running pandemicscientists are already anticipating Next a. They scour the planet for animal viruses that, like SARS-CoV-2could spread to the human population and cause severe disease globally.
They just found one. And his nasty.
In 2020, a team of Russian scientists collected a few horseshoe bats from Sochi National Park in southern Russia. The Russians have identified a new virus in these bats, which they call Khosta-2. Behaviourally, the virus seemed to have a lot in common with SARS-CoV-2.
Two years later, a separate team – including scientists from Washington State University and Tulane University – tested Khosta-2 with another newly discovered Russian bat virus, in the hope to determine if they are capable of infecting people. And, if so, whether our antibodies have a chance of stopping them.
The first results, which the team described in a new peer-reviewed study published last week in the scientific journal PLOS pathogens, are of concern. The second bat virus didn’t seem so contagious. But Khosta-2, on the other hand, took a liking to human cells.
“We tested how well spike proteins from these bat viruses infect human cells under different conditions,” the scientists wrote. “We found that the Khosta-2 virus spike could infect [the] similar to human pathogens using the same entry mechanisms.
Equally troubling, Khosta-2 was found to be “resistant to neutralization by serum from individuals who had been vaccinated against SARS-CoV-2.” In other words, our body’s defenses against COVID-19 might not protect us from a hypothetical illness caused by Khosta-2.
The implications are clear. We would need better antibodies to beat Khosta-2. “Our results highlight the urgent need for further development of new, more protective vaccines,” wrote the scientists behind the new study.
Like SARS-CoV-2 and the hundreds of other so-called sarbecoviruses, Khosta-2 uses this spike-shaped protein on its surface to grab onto and infect a host’s cells. But the vast majority of sarbecoviruses can only infect species that are their usual hosts. Bats, typically.
What makes Khosta-2 special is that, like SARS-CoV-2, it can also infect people, at least under laboratory conditions. What makes Khosta-2 particularly scary is that it seems to ignore the antibodies that currently work against SARS-CoV-2. Again, under laboratory conditions.
“The more we disrupt ecosystems and allow new mixtures of species and viruses, the more we spin nature’s wheel.”
— James Lawler, University of Nebraska Medical Center
There is a lot of uncertainty here. The Tulane-Washington State University team did not attempt to infect real humans with Khosta-2. To test for infection, they exposed the Russian bat virus to human cell cultures. To test our immunity potential, they exposed the virus to COVID antibodies. “We can only test what we can test,” Michael Letko, a virologist at Washington State University and one of the study’s authors, told The Daily Beast.
But the immunity test in particular was not necessarily representative of how our immune systems actually work, something the study authors readily admit. “The immune response in an individual will be multifaceted, encompassing innate and adaptive responses and cell-mediated immunity,” Letko said. “We only looked at neutralizing antibodies in this study.”
So don’t panic just yet. There are many animal viruses, many of which are closely related to SARS-CoV-2 or use at least some of the same biological mechanisms to infect their hosts. Most have never infected a human and might not even be able to do so under real conditions outside of a laboratory.
With further study, Khosta-2 could become a scientific red herring. A virus that looks much scarier than it actually is. “We’re struggling to accurately predict which ones will crack the code to become effective human pathogens,” James Lawler, an infectious disease expert at the University of Nebraska Medical Center, told The Daily Beast.
But there’s no denying that as the human population grows and cuts down more and more forests for farms and cities, they come into close contact with more and more exotic animal species. Every encounter is an opportunity for an animal virus to infect people – a process scientists call zoonosis.
“In general, we could say that the risk of zoonosis increases for many types of viruses,” Letko said. Consider the recent history of infectious diseases in the human population. SARS-CoV-2 is just the last animal virus to spread to humans, after the bird flu virus, SARS-CoV-1, MERS and others.
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The most useful thing we can do, besides stopping cutting down the forests where bats and their viruses live, is to develop vaccines that work against a wide range of similar pathogens. There are many universal coronavirus vaccines in development that scientists hope will work against current and future variants of SARS-CoV-2.
The same “pan-coronavirus” vaccines could also work against sarbecoronaviruses such as Khosta-2, Letko said. We can’t say for sure until we test them. But as COVID funding dwindles, intensive testing could slip further and further into the future.
What if these universal vaccines don’t work against Khosta-2, we might need a whole new one vax formulations, those that are even more widely effective. Barton Haynes, an immunologist at Duke University’s Human Vaccine Institute who is developing a new pan-coronavirus vaccine, told The Daily Beast that the most likely outcome would be a mixture of separate shots which, taken together, could offer a broad protection against a whole series of sarbecoronaviruses. .
In this case, we could have a race on our hands. Can we develop these brand new vaccines faster than a new sarbecoronavirus – whether Khosta-2 or an as yet unknown cousin – becomes zoonotic and makes the jump to the human species? And can we get enough people to actually obtain vaccines on time?