In just a matter of weeks, two variants of the coronavirus have become so familiar that you can hear their inscrutable alphanumeric names regularly uttered on television news.
B.1.1.7, first identified in Britain, has demonstrated the power to spread far and fast. In South Africa, a mutant called B.1.351 can dodge human antibodies, blunting the effectiveness of some vaccines.
Scientists have also had their eye on a third concerning variant that arose in Brazil, called P.1. Research had been slower on P.1 since its discovery in late December, leaving scientists unsure of just how much to worry about it.
“I’ve been holding my breath,” said Bronwyn MacInnis, an epidemiologist at the Broad Institute.