Imagine you go to the quack, because of a slight dizzy feeling? 'I'm afraid medicine can't help you, but you've got it for the rest of your days. Be careful because this will mean you are more likely than average to have a car accident'. 'How much more likely?' you ask. I have no idea he replies. Would you stop driving your DC about?
Imagine your friend works for the govt stats office. She tells you that car manufacturers and govt have been conspiring to under-report car accidents. 'Cor' you say, 'how much are they fiddling the numbers'. 'That's just the problem no-one knows because it's all hush hush'. Would you stop driving your DC about?
I'm guessing most people would carry on driving. In which case, why do people use the exact same reasons for not vaccinating?
The anti-vaxer reasons that uncle Bert gets hay fever, hay fever is hereditary and something to do with immune system, vaccine damage is also something to do with the immune system, DC are related to uncle Bert, and are thus more likely than average to suffer vaccine damage. They thus don't vaccinate them.
The anti-vaxer believes that the evil quartet of doctors, scientists, govt and pharma conspire to under-report vaccine damage. All part of their thirst to play god, and make lots of money by making people ill, not forgetting generous measures of incompetence and stupidity. They reason that vaccine damage is under-reported so they don't vaccinate their children.
I have never seen any attempt to quantify whether either 'the more susceptible than average' or the conspiracy theory could plausibly be sufficient to justify not vaccinating. It's incredible lame. Many anti-vaxer start from a position of prejudice against vaccination. They then compile a long list of selective quotes, mis-quotes, anecdotes, quasi-scientific speculations, and conspiracy theories. They say this list is evidence, and that their prejudice has become a rational analysis. It isn?t. It?s an uncritical list of unquantified elements which are superficially consistent with their position.