How do mutations arise?
They can occur by “mistake” (due to errors in copying the RNA when the virus replicates), through interactions with other viruses that are infecting the same host cell, or due to changes induced by the host’s own immune system.
Most mutations have no effect on the spread of the virus — in other words, they are neutral — but mutations can also be detrimental or beneficial to the virus.
Identifying mutations that could increase the virus’s ability to spread throughout the human population is critical, as it could help control the pandemic.
“As a growing number of mutations have been documented, scientists are rapidly trying to find out if any of them could make the virus more infectious or deadly, as it’s vital to understand such changes as early as possible,” explains senior study author Prof. François Balloux.
Of these, 273 have occurred repeatedly and independently. Recurrent mutations are important to study because their repeated generation suggests that they may have some advantage to the virus.
The research then focused on 31 mutations that have independently occurred at least 10 times during the course of the pandemic.