Though I'm fairly solidly pro-vax, I am noting some potential ironies and exceptions.

Most think "Boolean" thoughts, Vax="Good" or "Bad", but as you point out, some interesting in-between.

In the olden days, even bad vaccines looked good, as they generally protected you (usually a child) from imminent disease/death and you probably weren't going to live long enough to notice the bad side effects (if any).

Now that people live longer, there may be an "mRNA protects 60 yr old against 25% chance of Covid death w 5% chance of induced cancer death at age 80" kind of thing.

Still good odds (esp. since by that time they may have cancer cure?), but of course anti-vax community will say "See? All vax="bad". We as a society could say "stop these mRNA vaccines until long-term effects are better understood", but it seems going forward w us as guinea pigs still gives us best life option and yields useful information (until something better comes along).