Upvoted! I never questioned whether or not herd immunity is a real thing. But even if herd immunity does exist, and frankly I doubt the tourism point you made is enough to suspect otherwise, and even if vaccines were the greatest thing ever and clean and save and chocolate flavoured, I would still speak against any attempt to force them on people. But in that case it would probably not be necessary to make them mandatory anyway... You may be onto something, though, after all the point of herd immunity seems to be the only point in existence that only remotely makes sense. So making sure we actually check the basis for it is important.