Not a vaxxer or an anti-vaxxer

Merriam-Webster now defines:

Definition of anti-vaxxer
: a person who opposes the use of vaccines or regulations mandating vaccination

This is bizarre.

First, the English language does not use a double-x. Someone who boxes is a boxer, not a boxxer. A tax collector would be a taxer, not a taxxer.

Second, someone against mandates is anti-mandate.

Would someone call himself anti-abortion if he is against abortion mandates? Anti-gun if he is against gun mandates?

I believe medicine should be based on informed consent, but such a view is not defined as anti-vaxxer.