The study was just published in the medical journal PLOS Pathogens by a team of authors led by virologist Michael Letko from the Paul G. Allen School of Global Health at Washington State University (WSU).
Research Citation, Sheet Medical Xpress said Khosta-2 is a virus found from a small leaf-nosed bat species in western Russia, belonging to a subgroup of corona viruses known as sarbeco viruses. SARS-CoV-2 that causes COVID-19 is also a representative of the sarbeco virus.
“Portrait” of a bat that carries the Khosta-2 virus – Photo: João Manuel Lemos Lima/MEDICAL XPRESS
Initially, Dr. Letko’s team and two key collaborators, viral ecologist Stephanie Seifert and viral immunologist Bonnie Gunn, also from WSU, studied both Khosta-1 and Khosta-2 in bats. Russia.
They determined that Khosta-1 poses little risk to humans, but Khosta-2 has exhibited some disturbing characteristics.
Like SARS-CoV-2, Khost-2 can use its mutant protein to infect cells by attaching to a receptor protein called ACE2 – which is the familiar “gateway” of SARS-CoV. -2, found in human cells.
The team set out to determine if existing vaccines protect against the new virus using serum taken from a population of people who have been immunized against COVID-19. The result is ominous: Khosta-2 cannot be inactivated by current COVID-19 vaccines.
They also tested sera from people who had been infected with the current dominant strain of SARS-CoV-2, Omicron, but the antibodies were also ineffective.
Thus, it can be concluded that Khosta-2 is not only resistant to vaccines but also to immunity from former F0.
Fortunately, Dr. Letko and colleagues found that the new virus was missing several genes thought to be involved in the pathogenesis of human disease. However, there is a risk that Khosta-2 recombines with another virus that has already infected humans like SARS-CoV-2 and creates a dangerous “child”.
According to Dr. Letko, this finding shows that there is a real need to find a more universal vaccine against sarbecoviruses.
In recent times, after finding that “traditional” COVID-19 vaccines are becoming less and less effective against SARS-CoV-2 strains carrying many new immune escape mutations – most recently BA.4 and BA .5 Omicron – has accelerated the discovery of more universal vaccines, of which Pfizer or Moderna’s two-component (anti-Omicron component) vaccines are examples.
However, the ultimate goal of vaccine researchers around the world is still a “pan-coronavirus” vaccine, which is capable of fighting not only all past and future strains of SARS-CoV-2. but also against many other corona viruses.
As a participant in COVID-19 vaccine research, Dr. Letko emphasized that the family of viruses is an ever-changing list, so it is always necessary to expand the vaccine design so that its attack power is universal. more shouting.
While hundreds of sarbecoviruses have been discovered in recent years, mainly in bats in Asia, most are not capable of infecting human cells.
The Khosta-1 and Khosta-2 viruses were discovered in Russian bats at the end of 2020, and they did not appear to be a threat to humans at first, so they were not noticed by the scientific community.
Genetically, the strange viruses in Russia look like some other viruses that have been discovered in other parts of the world, but because they are not so similar to SARS-CoV-2, no one thinks they are real. It’s anything to get too excited about,” Dr. Letko explains.
“But when we looked at them more closely, we were really surprised to see that they could infect human cells,” he continued. this virus, where are they coming from and what areas are involved.”