It’s a political decision, not a science one
Though science advice will be needed for the safe lifting of restrictions. And targeting relaxations towards those who would pose lowest risk of overwhelming NHS (because vaccination means you are so likely only to have the mild illness) does have a logic.
But of course set against that the effect that the jab will be reducing the risk to the vulnerable and the elderly to that which the healthy young population already enjoys, then there might be no need
But we can’t control what other nations do, so there may be formal restrictions on international travel