The study, led by Dr Katrina Lythgoe (Big Data Institute) and published today in Science, used deep sequencing to obtain multiple SARS-CoV-2 genomic sequences per individual to characterise the genetic variation of their viral population.
The results indicate that acute SARS-CoV-2 infections tend to have few, if any, genetic variants. Even when mutations do arise, it will be hard for them to spread as most of the time only the most common variant will be passed on and the others will be lost. In rarer cases, a minority variant might get through and become the consensus sequence, or there might be co-transmission of multiple variants, leading to a mixed infection. This underlines the need to drive down the number of infections, making these rare events even rarer, and continued monitoring of SARS-CoV-2, so we can detect concerning new variants and act before they become dominant in a population.