EARLIER this year, Dido Harding, whilst heading England’s coronavirus test and trace system, said that no one could have predicted that new variants of SARS-CoV-2, the virus that causes covid-19, would emerge. Of course this was predicted, and while some people questioned Harding’s statement, many still seem surprised that the virus continues to mutate.
With covid-19, we have taken a largely reactive approach to new variants. As each emerges, we evaluate the genomic changes, and then attempt to establish whether these mean it represents a greater health threat. But it is critical that we start to take evolution, rather than just genetic change, into account, especially given the recent announcement that cases could reach 100,000 per day in the UK as it opens up – accelerating the rate at which new variants may emerge.
In long-lived organisms, like humans, individual genetic mutations don’t tend to have much of