My folks use FB to keep in contact with a large circle of family and friends and it works very well for that, moreover, this is the case for literally 100's of millions if not billions.
I don't use it, but there's no reason for people not to if they find it useful.
A lot of people find not living in reality useful, AND they are still allowed to vote; how is that working out for the rest of society.
Until we have a better system for running countries that doesn't allow crazy and uninformed people to vote, maybe getting rid of some the sources of crazy information can at least help.
RFK Jr has been leading the vax pro-safety charge for some time (not anti-vax), and I think is making a difference.
(I know with all the closed minds on HN, this'll get downvoted to hell, but if you haven't done your own research into the dangers of vaccines, then you'll stay closed.)
No there are not.
Overall, they are exceptionally safe. When you combine the fact they are reducing potential disease as well and then compound that because of the externalization of the viral spread of such diseases (one infection creates multiple more) then they are exceedingly safe.
And where there are 'issues', they are not in the range of the ridiculous conspiracy theories thrown about.
The anti-vaxxers, especially celebrities, are a serious threat to public health.