A supervisor disinfects the handrails of a bus in Wellington, New Zealand Hagen Hopkins/Getty Images
It may seem surprising, but more than a year after the coronavirus pandemic began, we still don’t know the relative importance of the different ways of catching covid-19: by touching contaminated surfaces or by breathing it in.
In March 2020, UK government advice was that face coverings weren’t generally needed and that people should focus on frequent handwashing, the use of hand sanitiser and on wiping down surfaces.
Since then, the evidence has mounted that the virus can spread through the air,…
