Of variants, vaccines and inequity

Vaccine inequity that leaves large populations unvaccinated raises the risk of dangerous variants emerging which will affect the whole world. — Reuters

Once upon a time there was a coronavirus. It was a nasty little thing that kicked off an epidemic in East Asia and made lots of people really sick. Eventually, human immune systems built enough defences against it. And then it became no more of a threat than the common cold.

No, I’m not talking about Covid-19 but about an ancient coronavirus that caused an epidemic 20,000 years ago. Scientists pieced together this story by analysing human genomes. So severe was the epidemic that it left its mark on human DNA.