If the argument is “mandates are wrong”, we’ve had them for over 150 years. If the argument is it’s not safe, its FDA approved and has been administered over a billion times.
https://www.healthline.com/health-news/vaccine-mandates-in-s...
https://www.cdc.gov/vaccines/imz-managers/guides-pubs/downlo...
https://www.cdc.gov/vaccines/schedules/hcp/imz/child-adolesc...
EDIT: @LurkingPenguin: While this is a good point, the data shows that vaccination protects against an intense infection resulting in the need of ICU and ventilation care (protection having been infected by COVID and recovering from previously does not).