Isn't this just an argument from ignorance? We probably have written records from the last pandemic. If you really think that the parent post is incorrect, why not furnish evidence?
that's not what argument from ignorance means: https://en.wikipedia.org/wiki/Argument_from_ignorance. While there's definitely anti-vaxxers that making the "well we don't know whether it's safe/effective", it's obvious that this thread isn't arguing that. It's possible to acknowledge that the virus is deadly and the vaccine is safe and effective, and still be against mandates on moral grounds (consequentialism vs deontology). I suggest you better understand the position of your opponents rather than immediately going for the "what a bunch of entitled snowflakes" conclusion.