If parents want their children to get a vaccine, they will have that opportunity.  If teachers want to get a vaccine, they already have the opportunity.  There's no reason to force them to do it.  This policy would create an underclass of students who aren't vaccinated, and a group of unemployable, but qualified, teachers who can't work.  What would the benefit be?  These children are not in danger from the virus, and the teachers can make their own decisions.