The scientific debate over the effectiveness of masks in schools has heated up, calling into question whether mask-wearing will help students, as schools across the country open in the midst of the delta variant surge.

Some physicians and scientists have recently claimed that the best evidence shows that masks are not an effective measure against the coronavirus, that the risk of the virus to children is small, and that masks can have a substantial downside for children. Others have countered that universal masking in schools is a necessary measure until vaccines are widespread among young children.