Mask wearing and COVID-19: What does the evidence say?

British surgeon, Joseph Lister, suggested in 1867 that wound infections were caused by the microscopic entities described by Louis Pasteur. From 1897, surgeon Johann Mikulicz of the University of Breslau (now Wroclaw, Poland) wore a face mask during operations and a study of more than 1000 photographs of surgeons in operating theatres in US and European hospitals between 1863 and 1969 showed ‘that by 1923 over two- thirds of them wore masks and by 1935 most of them were using masks’ (Strasser and Schlich, 2020).

By the spring of 2020 most of us were using masks, too, as the COVID-19 era began. However, as the post-pandemic dust settles it appears that the evidence for and against the use of masks has been recruited to serve diverse agendas, whether political or scientific.

In April 2020 the Scottish Government's National Clinical Director, Professor Jason Leitch, asserted that ‘the global evidence is masks in the general population don't work’ (BBC News, 2020); yet in May 2020 a cross- sectional survey of 206 UK community pharmacists found that 72% wore an N95 protective mask and 28% wore protective gloves and apron ‘in addition to safe distancing and protective masks’ (Zaidi and Hasan, 2021).