Men of science have often committed the cardinal scientific sin of forgetting they don't know what they don't know, and when worried citizens suggested maybe we don't know about all the risk factors of this rapid development, they often resorted to pointing out the ignorance of these non-scientific folks and ridiculing their beliefs. Sometimes it was their own ignorance they couldn't see, and sometimes the actions they took to invalidate the concerns of others backfired in their ultimate goal to make this new technology as widely adopted as possible. The way you want the world to work isn't how it works, and ridiculing people into submission won't achieve what you want. If you don't recognise any validity in people's concerns about vaccination then they won't listen to you, nor will the people on the fence, because there is some validity. You and they might disagree on how much there is, and you might make progress in closing that gap, but dismissing them is entirely counterproductive because, among other things, it is not entirely factual.