Biologists from Australia have found that the emergence of more and more dangerous strains of the SARS-CoV-2 coronavirus is due to the growing pace of its evolution. Previously, the virus accumulated no more than two mutations per month, but now the figure has increased to 10-15, writes the RIA Novosti news agency, referring to the medRxiv portal.
During the year, four variants of SARS-CoV-2 were recorded in the world, selected by experts from the World Health Organization in the group with the highest risk assessment. These are the British (alpha), South African (beta), Brazilian (gamma) and Indian (delta) strains of the infection. These options spread faster than others and provoke a more serious course of the disease. In addition, dangerous strains are less susceptible to antibodies that have appeared in the body as a result of vaccination or after a previous infection.
Employees at the University of Melbourne believe that the coronavirus has begun to mutate faster under the influence of positive selection. Scientists have studied the genetic sequences of the SARS-CoV-2 virus from the open GISAID database, and estimated the rate of evolution of the pathogen using different models.
The analysis showed that the rate of evolution of the coronavirus varies greatly between strains, and the emergence of new variants of the pathogen is largely determined by an increase in the rate of evolution. In some periods, the rate of evolution of SARS-CoV-2 exceeds the background phylogenetic four times.