One thing we do know is that telling people that they are stupid is an especially stupid way of trying to change their mind.
That middle class mummy, who has made up her mind because of talk on Mumsnet has the safety of her "DD" or "DS" as her utmost priority, and even if her "DH" would prefer the kids to be vaccinated he's going with the easy route. (Have a look at Mumsnet if the somewhat infantile abbreviations don't mean anything)
There's a kind of peer group pressure at work, underscored with a value that is impeccable it's honesty and purpose, ie doing their best for the kids. She loves her kids, she wants the best. Realistically who can tell a mother that she's doing it wrong by insisting that she's hurting children and expect her to change her mind straight away? That's just bullying.
People seem to be capable of making a 180 turn through absorbing different information that appeals to their core status in life / reasons for belief. That might be very different to how many other people (let's call them the persuaders) see things. It's up to those persuaders to make a better case that appeals to the core values in a way that is actually respectful, because as sure as eggs are eggs, a facile presentation will not change minds, and might even add another layer of conspiracy.
At that point I'm afraid I'm out of ideas, over to the sector experts for a plan of action that will persuade.
Edit, it just occurred to me as an enthusiastic believer in Galton's Ox that maybe it's not necessary to change all minds, just enough to maintain the herd's immunity.
Middle East Peace Expert. Military strategist. Former economist and epidemiologist.
Not always entirely serious.
-Still learning -