You need to have worked in a school/taught to understand the risk to teachers:
Without shift working/reduced timetables there will be classes of 30+ pupils in state secondary schools (in rooms where it will be impossible to have "social distancing")
Corridors are generally narrow - staggered lesson timings will help to reduce contact, but how long will virus/droplets persist in narrow and poorly ventilated walkways?
Teenagers "live forever", very few will give a shit about wearing masks let alone washing hands (number of times that I have told pupils to wash the snot off their hands after they have caught a sneeze, only to be looked at as if I were mad as they wiped the snot on to their clothes/pencil case/bench).
Large numbers of pupils used to congregate in the toilets while they ate their sandwiches - good luck with policing that one, unless you want to be accused of being a "paedo" (pupil speak)
The list could just go on, thank goodness that I took early retirement
Interesting that US has started to notice a rise in the number of deaths of teachers since starting back at the start of August. Young people can have the virus (they may not suffer as badly from infection) the virus does not "decide" that a young person is not a suitable surface/host to infect.
LP12, Ittok (black), DV10X5, NVA Phono 2 (twin supply), NVAP50, Art Audio Quintet 15w power amp, NVA LS5 cable, Rega Ela mk1's.
Sony CDP XB930.