Prof Naismith said: "The Office for National Statistics survey results on prevalence shows that the Scottish and English approach to masking, although formally different since July, has made no meaningful difference to delta.
"In both countries, very high levels of prevalence have continued for months. Thus the new changes announced are unlikely to have much of an impact
if omicron does indeed spread rapidly."
Experts remain divided on how much impact
face masks have in preventing the spread of Covid. Some believe they are only useful when social distancing cannot be maintained, while others think they prevent the picking up of virus particles in the air even when people are not close.
Robert Dingwall, a professor of sociology at Nottingham Trent University and a former government Covid adviser, said: "We can certainly say with confidence that all the extra restrictions in those nations do not seem to be having much effect, given that the trajectory of infections does not differ markedly from that in England.
"However, we cannot then go on to single out one element and draw conclusions about that. Mask mandates are only one part of the package, and the comparisons often lack details about enforcement and compliance.
"I hear, for example, that Aberdeen is much more relaxed than either Glasgow or Edinburgh – and I suspect that once you get into smaller towns there is very little going on.
"In my view, the only thing that really has an impact on transmission is
working from home and reducing social contacts altogether, but the Government is desperate not to stall
the back to the office movement."
