The writer is a science commentator

Saturday marks exactly two years since I first wrote about an unexplained viral pneumonia affecting 59 people in a Chinese city I had never heard of. The apparent link to a live animal market, echoing the origins of Sars-1, gave me a vague sense of foreboding but no idea of what was to come. The World Health Organization has since recorded 300m infections and 5.46m deaths.

Two years on, the beginning of 2022 is redolent of winters past: UK hospitals are filled with Covid-19 patients; coronavirus briefings, in which advisers Patrick Vallance and Chris Whitty play stony-faced Cassandras to Boris Johnson’s Pangloss, are back on British screens; the reopening of schools amid rampant spread feels as much on a knife-edge this year as it did last January.