Appearing on Wednesday's show, the 67-year-old explained the way young children use their masks could actually spread the virus even more than before. His comments come hours after the government announced that face coverings were now mandatory in communal areas and corridors for students in areas of England that are subject to stricter coronavirus restrictions.
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"I think people have become very concrete in their thinking, so corridors and communal areas are now being considered more risky than classrooms," explained Dr Hilary. "Why? The doors are open between a corridor and a classroom, there is no cut off, the air circulates and mixes, droplets will move.
"It is sensible to say that if you cannot socially distance as you can in a classroom and take other measures in a classroom, in those communal areas where the children find it more difficult to socially distance, it makes sense to take the precaution of wearing a face covering."
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He added: "We don't know what level of protection that offers, but the consensus is that it's going to offer some protection for age groups 12 years of age and above. There is more evidence that younger children actually could spread the virus more by wearing masks, because of the way they use masks.
"So I think we need to get away from the concrete thinking, there is no right or wrong, nobody really knows the level of protection, wearing a face covering alone is going to make."
The World Health Organisation (WHO) has said children aged five years and under should not be required to wear masks. This is based on the safety and overall interest of the child since most are not able to put them on without help.
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