{"id":15138,"date":"2026-07-03T06:00:00","date_gmt":"2026-07-03T10:00:00","guid":{"rendered":"https:\/\/cov19longhaulfoundation.org\/?p=15138"},"modified":"2026-06-18T13:00:52","modified_gmt":"2026-06-18T17:00:52","slug":"scientists-recreate-covid-19s-evolutionary-journey-in-a-test-tube","status":"publish","type":"post","link":"https:\/\/cov19longhaulfoundation.org\/?p=15138","title":{"rendered":"Scientists recreate COVID-19\u2019s evolutionary journey in a test tube"},"content":{"rendered":"\n

Scientists and doctors keep closely monitoring viruses that could jump from animals to humans, such as emerging strains of avian flu and bat coronaviruses.<\/h2>\n\n\n\n

A key step in the origin of many pandemics occurs when an animal-borne virus infects humans and then evolves to spread more efficiently from person to person.<\/p>\n\n\n\n

For that reason, scientists and doctors keep closely monitoring viruses that could jump from animals to humans, such as emerging strains of avian flu and bat coronaviruses, as well as those such as hantavirus and Ebola<\/a> that have already crossed into humans but, for now, spread poorly among people.<\/p>\n\n\n\n

In just a few months, the researchers recreated in a test tube the evolutionary path the coronavirus followed during the COVID-19 pandemic<\/a> \u2013 from the original Wuhan strain to the emergence of the highly contagious Omicron variants.<\/p>\n\n\n\n

This achievement resulted from a new collaboration among the laboratories of Prof. Gideon Schreiber of the Weizmann Institute of Science, Dr. Jir\u00ed Zahradn\u00edk of the First Faculty of Medicine, Charles University in Prague, and the BIOCEV Center.<\/p>\n\n\n\n

The findings, published in Nature Communications under the title \u201cStringent selection drives convergence toward omicron-like SARS-CoV-2 receptor-binding motifs,\u201d raise hopes that in the future, scientists could predict how viruses are likely to evolve and under what conditions new waves of infection could emerge.Weak selection pressure leads to multiple viral variants<\/strong><\/p>\n\n\n\n

The experiment simulating this scenario, conducted at Weizmann, was led by Aviv Shoshany from Schreiber\u2019s team. Under weak selection pressure, by contrast, many viral variants survive, and advantageous mutations become enriched without taking over completely. This scenario was simulated by Ruojin Tian, Dr. Miguel Padilla-Blanco, and Dr. Martin Mokrej\u0161 from Zahradn\u00edk\u2019s group in Czechia.<\/p>\n\n\n\n

Zahradn\u00edk, who previously did his postdoctoral work in Schreiber\u2019s lab, focused on weak selection, while the Weizmann lab staff focused on stronger selection. \u201cWe found that if you begin with Omicron, even if it\u2019s weak, it\u2019s stable and remains there. We worked on only a section of protein in the virus, and most of the mutations were in that segment.\u201d<\/p>\n\n\n\n

\u201cIt took only a few months to make our discovery, but we spent more than two years preparing a journal article for publication, because we had to conduct many tests, including mathematical calculations,\u201d Schreiber recalled. \u201cIt was unbelievable. Billions of people were infected, but for all, there was the same result \u2013 we found the essence of the evolution of the virus. There aren\u2019t many cases like that.\u201d<\/p>\n\n\n\n

In August 2021, Schreiber and colleagues published the results of an in vitro evolution experiment that identified a pair of mutations in the coronavirus<\/a>\u2019s binding site that make the virus highly contagious by improving its ability to bind to receptors in the human respiratory tract.<\/p>\n\n\n\n

About three months later, the Omicron variant was first identified in South Africa<\/a>; when researchers sequenced it, they found the same pair of mutations. That was the moment Schreiber realized that the in vitro evolution method developed in his lab could potentially predict major turning points in the course of pandemics.<\/p>\n\n\n\n

Schreiber, who earned his degrees at the Hebrew University of Jerusalem and did post-doctoral work at Cambridge University, told The Jerusalem Post<\/em> in an interview that evolution proceeds through mutations and natural selection. To survive and spread, viruses replicate at high speed, which can often lead to genetic errors that accumulate, producing new variants. In the new study, the researchers replicated the gene encoding the coronavirus binding site using a deliberately error-prone mechanism, thereby simulating in \u201cfast forward\u201d the appearance of mutations.<\/p>\n\n\n\n

Using genetically engineered baker\u2019s yeast cells, they exposed millions of resulting variants to human receptors and, imitating natural selection, retained only those that still bound successfully. By repeating cycles of mutation and selection over and over, the scientists reconstructed the evolution of the virus-human interaction over the course of a whole pandemic.<\/p>\n\n\n\n

At the starting line of this evolutionary race in a test tube were the original Wuhan strain and several variants that emerged during the pandemic \u2013 including Alpha, Beta, and Omicron. The researchers studied how their binding sites evolved under two scenarios \u2013 strong selection pressure and weak selection pressure. Strong selection pressure is a situation in which only a small number of viruses survive each evolutionary stage, allowing advantageous mutations to rapidly become dominant.<\/p>\n\n\n\n

\u201cNo matter which viral variant we started with, under strong selection pressure, a variant remarkably similar to Omicron and its sub-variants emerged early on and rapidly took over the entire population,\u201d Schreiber said. \u201cThe exact same trajectory was observed during the coronavirus pandemic, which has not undergone another major shift since Omicron appeared and became dominant at the end of 2021.<\/p>\n\n\n\n

\u201cSome future pandemics that spill over from animals to humans may follow a similar path \u2013 accelerated evolution culminating in the dominance of a viral variant that is highly contagious and specifically adapted to bind to human receptors,\u201d Schreiber predicted.<\/p>\n\n\n\n

The evolutionary pathway leading to Omicron dominance was not viewed under weak selection pressure \u2013 and computer simulations revealed why, he continued. During the mutation process, several mutations can sometimes arise simultaneously. If one mutation gives a new viral variant a survival advantage and helps it dominate the population, other mutations \u2013 those that are neutral or even detrimental \u2013 can \u201chitchhike\u201d alongside it and spread as well. The simulations showed that under strong selection pressure, advantageous mutations become dominant before the hitchhikers get a chance to accumulate. Under weak selection pressure, however, beneficial mutations drag many additional mutations with them, diminishing their own dissemination advantage.<\/p>\n\n\n\n

\u201cTo survive in their bodies, the virus had repeatedly to fight their residual immune activity and repeatedly infect receptors in the respiratory tract,\u201d Schreiber explained. \u201cThose are precisely the conditions of strong selection pressure, and our study shows they are essential for the emergence of Omicron \u2013 further supporting the hypothesis that it originated in immunocompromised people. Interestingly, when we started the selection from Omicron, both strong and weak selection pressures were sufficient to maintain the Omicron sequences, explaining why this variant persists in the general population. This highlights how important it is to properly treat immunosuppressive conditions such as AIDS before the next global pandemic strikes, and to protect immunocompromised individuals from infection and chronic disease.\u201d<\/p>\n\n\n\n

He concedes that today, the coronavirus arouses much less interest here and abroad compared to four years ago. \u201cPeople forgot, because of new crises, but next time, I hope we\u2019ll be better prepared to cope with pandemics. We have very good tools now to understand how they advance.\u201d<\/p>\n\n\n\n

\u201cThe in vitro evolution method we developed could be applied in the future to other viruses of concern,\u201d he adds. \u201cWe will be able to isolate viral proteins and investigate how they are expected to evolve under different scenarios. Our approach makes it possible to identify dangerous variants before they become dominant, helping focus efforts on preventing the conditions that allow them to take over \u2013 and preparing for them in advance.\u201d<\/p>\n","protected":false},"excerpt":{"rendered":"

Scientists and doctors keep closely monitoring viruses that could jump from animals to humans, such as emerging strains of avian flu and bat coronaviruses. A key step in the origin […]<\/p>\n","protected":false},"author":2,"featured_media":15193,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[156,658],"tags":[],"class_list":["post-15138","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-evolution","category-zoonotic-transmission"],"_links":{"self":[{"href":"https:\/\/cov19longhaulfoundation.org\/index.php?rest_route=\/wp\/v2\/posts\/15138","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/cov19longhaulfoundation.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/cov19longhaulfoundation.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/cov19longhaulfoundation.org\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/cov19longhaulfoundation.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=15138"}],"version-history":[{"count":3,"href":"https:\/\/cov19longhaulfoundation.org\/index.php?rest_route=\/wp\/v2\/posts\/15138\/revisions"}],"predecessor-version":[{"id":15141,"href":"https:\/\/cov19longhaulfoundation.org\/index.php?rest_route=\/wp\/v2\/posts\/15138\/revisions\/15141"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/cov19longhaulfoundation.org\/index.php?rest_route=\/wp\/v2\/media\/15193"}],"wp:attachment":[{"href":"https:\/\/cov19longhaulfoundation.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=15138"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cov19longhaulfoundation.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=15138"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cov19longhaulfoundation.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=15138"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}