Is the coronavirus evolving and will it become more or less deadly?

“FORTUNATE” isn’t a word that often comes up in relation to the coronavirus pandemic, but in one respect it is true. In the nine months that the virus behind covid-19 has been circulating widely, it has hardly mutated at all.

“We are fortunate that the virus is not mutating fast,” says Sudhir Kumar at Temple University in Pennsylvania. A rapidly mutating virus could evolve into different, possibly more virulent, strains. “So it’s good to have a low diversity” among the viruses currently circulating, he says. However, this could be…