People risk their lives for their jobs all of the time and deal with with varying risks from fluctuating circumstances(eg. Being an electric lineman during a storm rather than during preferable weather, responding to an armed suspect rather than pulling someone over for a routine traffic stop, etc). Many jobs are MUCH more dangerous than the threat covid poses to a GSI, especially given proper precautions. I agree that it is very unfortunate that this is the way things are and I do empathize for the GSIs. That being said if you don't want to deal with the increased risk your job has undergone under any circumstances then quit. Your employer will still have its demands and if thats in person classes in this case then thats what it is. If enough people feel the same and quit they'll hire others, if they no one wants the job they'll raise pay, and if that doesn't happen then they'll simply move things to online like the GSIs want.