I have always said that, after the elderly and vulnerable, all front line staff should be next. That would include Police, Fire, Ambulance of course but also teachers, bus drivers, refuse collectors, shop workers etc.
I did hear a few weeks ago that teachers are not further up the list because, although the threat is felt, the number of deaths don't put them into a higher category.
Sounds harsh but seems reasonable in the circumstances.
A friend's son is front-line police and has health issues. He wasn't able to get through the online booking system but was able to get thro his GP.