Supermarkets and delivery drivers would seem to be a bit harder though? So unless there's a specific reason to prioritise one profession over another, as there was with health and social care staff, then targeting by vulnerability and then age would seem reasonable until evidence is there to support doing it different?
The DVSA would have to get involved for HGV drivers, as our licenses carry the relevant categories to drive Class 2 and Class 1, they could also pull up PSV drivers from that, but shop staff, Amazon drivers, Food Van delivery drivers etc you'd need to get into the tax records to show their employer.
I don't see how a secondary teacher is any more at risk than a supermarket worker, its a set groups of pupils, who will all be tested, sat a specific distance away and all masked up. Compare that to Supermarket workers who are out in the aisles with hundreds of random strangers passing them each day, staff touching surfaces all the time, touching stock that has been pawed by god knows who. Drivers, both the likes of Amazon, Tesco, Asda, Morrisions etc home delivery drivers are going from warehouses and shops and peoples homes and could have a valid case for saying they are more at risk than teachers. HGV drivers, while its a solitary job, do go in and out of warehouses and travel across the UK. Saturday I went to Heywood, then a Sainsburys RDC in Stoke to deliver, then Cannock to pick up a load of Pot Noodles that was destined for Cumbernauld nr Glasgow.