I don't think this is a safe thing to say about mRNA vaccines, which are brand new. IIRC one of the vaccines is essentially an old-style vaccine made for COVID, and for that one you may be able to reasonably say that, but not the new stuff that has never been mass-deployed before.

Nor does this mean they're automatically bad either. There's always a first time for something new. I'm just saying that it isn't really justified to apply decades of experience with one type of vaccine to another blindly.