Professor Carl Heneghan is the director of the Oxford Centre for Evidence-Based Medicine, and Tom Jefferson is a senior associate tutor. Both have very good affiliations, as does the CEBM itself, so I’m extremely surprised that they seem to have overlooked the possible benefits of source control.
Nothinguptop may have a point, in a perverse sort of way; the ‘symbolism’ of masks may itself be effective in reducing cross-infection. I find that seeing people wearing masks and having to remember to use one myself does act as an effective and constant reminder to be careful.