Professor Philip Nolan:

There are many things that Professor Heneghan has said that I disagree with. He is right in the sense that there is no evidence that they do any harm. The evidence that supports their utility is good but not of the kind of very high standard that we would require for an intervention that might cause harm. I am certainly more than satisfied that the evidence available to us now supports exactly Dr. Glynn's position that in addition to all the other things that are more important, these are a very useful adjunct in circumstances where we cannot maintain the 2 m-plus physical distancing that we might otherwise like to.