I'm guessing that (after Hancocks words above) that Gav is going to announce all teachers will be vaccinated and a slight delay in returning to school until this happens. This will also explain the 12 week delay between doses as it will free up some vaccines.
However as there appears to be no scientific evidence that the jab stops you getting it, nor stops you spreading it, will this not add to the school problem which is asymptomatic people with no PPE or SD mixing with lots of people and then bringing it home. So vaccinated teachers unknowingly bringing it home after contracting it due to mixing with hundreds of unvaccinated children.