New coronavirus in sight! In Russia, American scientists have discovered a cousin virus of Sars-Cov-2 in bats, according to a study published by Washington State University in the journal PLoS Pathogens. Called Khosta-2, this virus could infect humans, and, like some Omicron sub-variants, escape immunity conferred by Covid vaccines. What to fear from a next pandemic?Contamination of human cells and immune escapeDiscovered in 2020 by a team of “virus hunter” scientists, Khosta-2 was discovered in bats within the Russian national park of Sochi, without however causing the concern of American researchers, who then did not think that it could represent a threat to public health. Already in bats in Russia, scientists had unearthed a sister virus, Khosta-1, which, after laboratory examination, had proved incapable of contaminating human cells. But the relative serenity of scientists was disturbed by in-depth analyzes carried out on Khosta-2 in the laboratory, which demonstrated that this new coronavirus had the capacity to infect human cells. Khosta-2 appears to bind to the same protein, ACE2, as SARS-CoV-2 to enter human cells. “Receptors on human cells are the pathway by which viruses enter cells,” virologist Michael Letko, a Washington State University professor and lead author of the study, told Time. To complete this disappointing discovery, additional analyzes have demonstrated that Khosta-2 would also have the ability to escape the immunity conferred by an infection and an anti-Covid vaccination. “It is worrying to see that there are viruses circulating in nature which can bind to human receptors and are not neutralized by current vaccine responses”, warned Professor Letko. No contamination reported in humans However, the researchers want to be reassuring. To date, no human contamination has been reported. In addition, according to the results of their analyses, the Khosta-2 coronavirus does not seem to have the genes likely to cause serious forms in humans. Which could evolve if Khosta-2 starts circulating and mixing with SARS-CoV-2 genes. “The concern is that SARS-CoV-2 could spread to animals infected with Khosta-2, recombine, and then infect human cells. They could be resistant to vaccine immunity and have more virulent factors”, explained Professor Letko, for whom anti-Covid vaccination must not weaken. However, according to the latest data collected by the WHO, a quarter of people around the world have still not received a primary vaccination against Covid-19.