tl;dr: Vaccinating kids good, but "Your individual beliefs are not more important than the health/safety of society" isn't an effective argument for convincing brainwormed anti-vaxxers or their lib enablers.

To anti-vaxxers it's just saying "the actions your beliefs are causing you to take are harmful, don't act on your beliefs act on my beliefs instead" which won't get you anywhere because by their beliefs, which they, y'know, believe, not vaccinating and convincing people not to vaccinate is less harmful than vaccinating., so it ust comes off as saying "I'm right you're wrong, surely you see that" which is super alienating and patronising and won't get you anywhere.

To the lib enablers it's saying "if we see people doing things we think are harmful we should always stop them and force them to do things our way", which gets you further than with the anti-vaxxers, but not by much, because if they believe that not vaccinating kids is harmful they're either wanking themselves off about individual freedoms, in which case you want to make arguments that target the contradictions in that nonsense, so talking about the rights of children or majority consensus or the tragedy of the commons, or they think the harm done by stopping the anti-vaxxers would be worse than the harm the anti-vaxxers do, in which case you want to shove heartbreaking pictures and stories of kids with measles and polio in their faces until they agree its worth it.

tldr;tldr: agree vaccinations should be mandatory, here's some reasons people disagree and ways to convince them.