There was a model presented on the BBC a while back - about holes in cheese - to explain why, with Covid mitigations, the most effective approach is ‘and’, not ‘or’.
Vaccines AND testing AND ventilation AND masks AND isolating the infected is more effective than any one of those individually.
Equally, it isn’t ‘education OR Covid mitigation’. The two are so intrinsically connected - pupils and teachers who are ill do not receive ir deliver an effective education - that it should be ‘and’ not ‘or’.
It’s very easy to equate ‘schools are physically open’ with ‘a good education is being delivered’. There were many weeks last term where my school was fully open but education of some or all was badly compromised by staff absence. When 1:1 TAs are the only adults left to stand in front of classes, with qualified teachers supervising their class own plus one or two others, it affects the education of both the children with SEN who have no support, and the classes as a whole.
In normal times, teachers might have a day or two off, maybe once a year or less. As the vaccinated DO catch Covid and MUST isolate for 10 days, the 5x longer absences, concentrated over the winter, will be an issue that will affect the education delivered to children even if they are physically within the school building.