Let's just call it what it is.
It's teachers wanting to be vaccinated for their summer holidays. There is the prospect of vaccine passports and people having their freedoms to go places and do things they could not do without being vaccinated and teachers are conscious they will soon be on a 2/3 month break and want to be able to do that.
It's another example of teachers using a public crisis to hold the govt to ransom and try and strongarm them into getting their demands. It's cynical and calculated and once again shows teachers up for the self-entitled grouping they are.
You don't see factory workers, police officers, carers, creche and nursery workers, bus drivers etc all threatening strike over this but teachers will and they only have a couple of months of half days left.