What is the science behind Covid-19 and schools?

Leah McCallum (left) and Rebecca Ross, S4 students at St Columba’s High School, Gourock, put on their protective face masks (Jane Barlow/PA)
Leah McCallum (left) and Rebecca Ross, S4 students at St Columba’s High School, Gourock, put on their protective face masks (Jane Barlow/PA)