It's unfortunate that it's necessary to provide this reminder within almost every message thread.

It's basically a straw man fallacy, and the fact that it's probably unintentional on the part of the committers tells you something about the single-mindedness of those doing the committing.

How do you know anyone has natural immunity? There are plenty of anti-vaxx conspiracy nutjobs that would happily lie about it to avoid getting improved 5G.