PORTLAND, Ore. (KOIN) – A recently discovered virus in a Russian bat is similar to SARS-CoV-2, the virus behind COVID-19, and is capable of infecting humans, according to researchers at Washington State University, who added if the virus were transmitted to people, current vaccines couldn’t prevent it from spreading.
The virus is known as Khosta-2. Its spike proteins are resistant to both the monoclonal antibodies and serum from people vaccinated for SARS-CoV-2. The two viruses belong to the same subcategory of coronaviruses known as sarbecoviruses.
“Our research further demonstrates that sarbecoviruses circulating in wildlife outside of Asia – even in places like western Russia where the Khosta-2 virus was found – also pose a threat to global health and ongoing vaccine campaigns against SARS-CoV-2,” said Michael Letko, a WSU virologist and an author of a study on the Khosta-2 virus found in the Russian bat.
Letko said the discovery of Khosta-2 highlights the need to develop universal vaccines that protect against sarbecoviruses in general, rather than just against known variants of SARS-CoV-2. There are groups working on a vaccine that would provide broader protection against sarbecoviruses now.
“Unfortunately, many of our current vaccines are designed to specific viruses we know infect human cells or those that seem to pose the biggest risk to infect us. But that is a list that’s ever changing. We need to broaden the design of these vaccines,” Letko said.
Hundreds of sarbecoviruses have been discovered in recent years, but most of them are not capable of infecting human cells.
Initially, when they were discovered in Russian horseshoe bats in late 2020, it appeared the Khosta-1 and Khosta-2 viruses were not a threat to humans. Letko said they did not look like SARS-CoV-2 and no one was very concerned about them. But after a closer look, researchers were surprised to find they could infect human cells.
He said that changed their understanding of the viruses, where they come from and what regions are concerning.
Letko worked with WSU faculty members to study the two new viruses. They determined Khosta-1 posed a low risk to humans, but Khosta-2 had some troubling traits.
Like SARS-CoV-2, researchers found that Khosta-2 can use its spike protein to infect cells by attaching to a receptor protein, called an angiotensin-converting enzyme 2, found throughout human cells.
The team then explored whether the current vaccines protect against the new virus.
Researchers used serum derived from humans who were vaccinated for COVID-19 and discovered that Khosta-2 was not neutralized by current vaccines. They also tested serum from people who had been infected with the omicron variant, but the antibodies were also ineffective against the new virus.
Letko said fortunately, the new virus lacks some of the genes believed to be involved in pathogenesis in humans. However, there is a risk Khosta-2 could recombine with a second virus like SARS-CoV-2.
“When you see SARS-2 has this ability to spill back from humans and into wildlife, and then there are other viruses like Khosta-2 waiting in those animals with these properties we really don’t want them to have, it sets up this scenario where you keep rolling the dice until they combine to make a potentially riskier virus,” Letko said.
Stephanie Seifert, Bonnie Gunn, Shuangyi Bai and Stephen Fawcett of WSU, along with Elizabeth Norton, Kevin Zwezdaryk and James Robinson of Tulane University, joined Letko as co-authors of the study.