WITH cases of coronavirus reported on four continents, health experts are concerned it could become a pandemic. The world is currently in the grip of two others – Aids and tuberculosis – while measles is on the rise again and polio stubbornly resists eradication. When smallpox was wiped out, some in the medical community were so high on their success they thought other infectious diseases would soon be licked. Fifty years later, this triumph remains unique…

This article was first published in The Guardian on 6 February 2020. To continue reading, click here.