I don’t don’t know what the rules will be but I would get vaxed just to “check all the boxes”.
I wouldn’t be surprised if this turns into some big thing at the last minute and they tell him, “sorry but you need to be vaxed to get on/off this plane.”
I didn’t plan on getting vaxed but getting 2 shots was a lot easier than dealing with the nagging I would have gotten otherwise.
This is a big moment. Check all the boxes.