I support abortion rights but hate this argument in particular, because bodily integrity of the child would be of interest as well.
HRT and plastic surgery are irrelevant here since they are voluntary choices.
They were trying to apply it to vaccination, which isn't comparable to abortion for reasons I explained and therefore the chant had no place there.
I do agree that the framing of abortion as a bodily integrity issue is missing a lot of other aspects, which is why we got dumb things like the heartbeat laws. But it is the argument I hear most activists make.
HRT and plastic surgery are relevant because they're choices you should be allowed to make about your body because they don't harm others. Not getting vaxxed doesn't satify that criterion. It's not a perfect comparison since one is an action and the other is the lack of action, but it's still an issue of the government controlling what you do with your body, which I argue is acceptable if and only if it's something that harms others.
To move forward, you have to prove that one particular unvaccinated person harmed another particular person in the case of covid. Good luck with establishing this causation!
Bodily integrity isn't a blanket rule. You have it only insofar as it doesn't harm others. Abortion, HRT, plastic surgery... fall into that category. Willingly spreading a deadly disease despite an easy and safe-ish preventative option does not.