Israeli scientists simulated the evolution of the virus during the COVID-19 pandemic in the laboratory

When the SARS-1 virus was reported in the early 2000s, humanity received a serious warning. But the outbreak quickly faded. As a result, the lessons were not “learned”: fundamental science did not receive large-scale investments, and preventive vaccines remained on laboratory shelves. In the spring of 2020, this came at a cost of trillions of dollars and millions of lives. The world was gripped by panic over the unknown, since no one could predict how the new pathogen, SARS-2, would behave.

Today, researchers are changing the very approach to combating pandemics, moving from delayed reactions to advanced modeling. Scientists were able to completely recreate the three-year evolutionary path of the coronavirus in the laboratory. They developed a method of directed evolution that allows them to predict the evolution of the virus. The work was published in the journal Nature Communications.

Instead of working with a dangerous live pathogen, biologists took only the isolated gene responsible for the receptor-binding domain – a kind of “hook” that the virus uses to cling to human cells. Using a special copying method that deliberately makes many errors, scientists have artificially created millions of mutant versions of this gene. These variants were then introduced into ordinary baker’s yeast cells, turning them into living factories that displayed a variety of mutations on their surface.

Yeast cells were passed through an artificial selection sieve, adding human respiratory receptors. The experiment showed that the trajectory of virus development fundamentally depends on environmental pressure. Under conditions of weak selection, beneficial mutations mixed with genetic debris, without producing a clear leader. But under conditions of harsh, strong selection pressure, when only single mutations survived, the same super-variant won over and over again.

This laboratory winner turned out to be strikingly similar to the Omicron strain, which at the end of 2021 supplanted all other varieties of the virus on the planet. The experiment brilliantly confirmed the medical hypothesis: the omicron was formed under conditions of severe selection pressure, most likely in the body of patients with severe immunodeficiency (including HIV). In the body of such a host, the virus lives for months, generating trillions of mutations, and the weakened but resistant immunity gradually cuts off weak variants and polishes the ideal strain.

The success of the experiment opens the era of predictive virology. Now, having discovered any new dangerous virus in animals, scientists can not wait for it to jump to humans, but can calculate in advance the trajectories of its mutations in vitro. This will make it possible to create vaccines and test systems even before the killer strain begins to destroy people.