Anti-vaxxer (casual and pejorative) used to lump together anyone who thought most or all vaccines were harmful. Now anti-vaxxer includes people opposed to forced vaccination, which can apparently include experimental vaccinations. The pejorative has been used in practice in 2021 to mean anyone who points at any reason at all why the COVID-19 vaccines might not be the best option, even if that means pointing to scientific analysis.

Oddly, it turns out that the definition change did not really happen in 2021 or even 2020, but has been a part of Merriam-Webster since 2018. That should leave people scratching their heads.