The SARS-CoV-2 virus appears to be constantly evolving. In just two years, the alpha, beta, delta, lambda, mo, and omicron species all became news headlines. Of course, this is a list of dozens of other corona species that have been identified but not considered important by the World Health Organization. So, is the rapid evolution of this coronavirus abnormal or are other viruses so similar? Experts answer this question.
“Viruses are constantly changing, but the multiplication process may be interrupted,” said Soman Das, an associate professor of medicine at Vanderbilt University Medical Center who studies the evolution of viruses, including the SARS-CoV-2 virus.
Mistakes (degrees, deletions, and random substitutions called mutations) occur when viruses use host cellular machines to copy their genetic material. While most random mutations can be harmful to the virus or have no effect at all, some mutations give it a competitive advantage. Some mutations may help the virus escape the vaccine or make it more contagious. Mutations that help the virus stay active longer and reproduce more easily are selected, that is, they remain. Thus, new species are created.
SARS-CoV-2 viruses, such as influenza viruses, RSV viruses, enteroviruses, and rhinoviruses that cause colds, carry their genetic information on a strand of RNA.
“Katie Kistler is a researcher at the Fred Hutchinson Cancer Research Center in Seattle, which studies the evolution of viruses.”
In comparison with the RNA of other viruses, the mutation rate of the SARS-CoV-2 virus is not particularly significant. In fact, its mutation rate is similar to the RNA mutation rate of common viruses such as the flu and other common coronaviruses that cause cold symptoms.
The end result of the mutant valley is that: the SARS-CoV-2 virus does not mutate at an abnormal rate; But other influential factors such as high virus transmissibility, transmission from animal to human, and the development of new therapies and vaccines may increase the number of SARS-CoV-2 strains in the short term. Jesse Erasmus, a virologist and assistant professor of microbiology at the University of Washington School of Medicine, said:
The SARS-CoV-2 virus, the virus that causes Covid 19, may appear to be more mutated due to the fact that it is more contagious than other common viruses and causes many more infections.
The actual rate of mutation per infection, if not slower, is similar to other common viruses. But the virus is constantly circulating among more people, giving it more opportunities to multiply and produce beneficial mutations.
The rapid changes in SARS-CoV-2 may also be related to its recent human leap. Until 2019, the virus was compatible with infecting animal hosts and, most likely, bats. Kistler said:
First, the virus must adapt to infect humans instead of bats. There are many beneficial mutations for the virus at this stage of transmission. After that, the adaptive evolution of the virus slows down a bit.
The 2009 H1N1 flu pandemic virus followed suit. Kistler said:
During the first stage of globalization and one or two years after its emergence, we see that the rate of functional change is higher and then decreases to a more stable baseline.
Scientists do not know how the evolution of SARS-CoV-2 changes when it goes from epidemic to endemic, but based on other pandemic viruses, they speculate that adaptive evolution may slow down.
Finally, the changes we see in SARS-CoV-2 are due in part to the rapid development of vaccines and therapies designed to stop it. “Compared to the early days of the world, there is now much more pressure on the virus to escape the drug measures designed to overcome it,” Dos told LiveScience.
We now have several vaccines, antibody combinations, plasma therapy and two drugs to fight Quid. It is the pressure that drives the selection of the virus. Some of the mutations that remain are mutations that help the virus avoid these challenges.