Maybe the line needs to be crossed, but denying that line and ridiculing the people who value the line is not helpful. Bodily autonomy/corporeal sovereignty was historically a cornerstone belief for the same people who now want to deny it from others, and that should not be taken lightly.
Interestingly enough, you appear not to identify with the group that has historically supported the right to abortion as a personal decision, have I interpreted that correctly? And you do identify with the group that believes vaccination should be a personal decision?
Helmet law would be a better comparison. The argument for requiring a seat belt isn't about protecting people from their own choices. It's because it's very easy to lose control when things get exciting if you're not belted into the seat. Now you're throwing around a two ton projectile and everyone else's lives are at risk.
This can't be the complete argument, because then it would only apply to drivers. If you're not wearing a seat belt and you're in an accident, you might become a projectile which can cause harm to others in the same vehicle.
If some person starts to link their identity to not believing in the vaccines, belittling them is not likely to help.
If it hadn't been made political, I would buy your comparison to seatbelts and drunk driving, but as it is, I think it is more comparable to putting a ban on male circumcision.
(Also, for the record, I think both sides of US politics has their own areas where they ignore evidence in favour of what is "correct" thinking for their side.)
If only more people were rational, and understood how to properly value "small risks with disproportionately large consequences". But there I go touting an ideology, again...
https://www.psychologytoday.com/us/blog/the-inertia-trap/201...