Oh, the good ol’ days, when we only had to dodge the odd snotty patient, germ-ridden child and perhaps every now and then employ the skilful sleeve-over-the-hand technique on public bathroom doors.

But since the outbreak of COVID-19, strict social distancing measures have been in place, with organisations such as the US Centers for Disease Control and Prevention recommending 2m of separation between people and the WHO recommending 1m.

However, these guidelines are based on a 90-year-old model of transmission that recent research has called into question, says Associate Professor Lydia Bourouiba, from the Fluid Dynamics of Disease Transmission Laboratory at MIT.

“Although such social distancing strategies are critical in the current time of pandemic, it may seem surprising that the current understanding of the routes of host-to-host transmission in respiratory infectious diseases are predicated on a model of disease transmission developed in the 1930s that, by modern standards, seems overly simplified,” she writes in a commentary in the Journal of the American Medical Association.