The authors of the new study noted that mutations that make coronavirus "more evil" may not appear in the future.
None of the known mutations of the coronavirus SARS-CoV-2 seemed to increase its infectivity, that is, the ability to be transmitted from person to person. A study on this subject has been posted on the preprint resource, bioRxiv. It has not yet been reviewed for publication in journals.
Scientists analyzed the data on the genomes of more than 15 thousand SARS-CoV-2 viruses from 75 countries. The information was based on studies that another scientific group published in a journal. Infection, Genetics and Evolution in a work on the genetic diversity of the virus.
“As mutations are documented, scientists are trying to figure out whether any of them can make the virus more deadly, because it is vital to detect such changes as early as possible,” said Professor Francois Balloux from Universitetskoye London College, lead author of the study.
The authors reported that coronaviruses have several ways to develop mutations: as a result of simple errors, due to interaction with other viruses and with the host immunity. Mutations can be both neutral and beneficial for viruses. Mutations of both of these species can become common if they are transmitted to the next generation of viruses.
Scientists have discovered 6882 mutations in viruses of a huge sample of SARS-CoV-2. For 273 mutations, they found evidence that they independently reoccur. Among them were 31 mutations that occurred at least 10 times during a pandemic.
A model of the evolution of the virus showed that none of the mutations was transmitted to descendants more efficiently than others. No evidence was found that any mutation improves transmission.
Scientists paid special attention to the mutation D614G, which is associated with the S-protein of the virus, as it was previously suggested that it is associated with an increase in infectivity. In this analysis, no association of the D614G mutation with increased transmission was found.
“We still expect the virus to mutate and its pedigree will finally split into different lines. But this does not necessarily mean that any of the lines will become more contagious or harmful, ”said Dr. Lucy van Dorp, co-author of the study.