Just framing this as a conspiracy theory nut might.

Exposure to conspiracy theories about vaccinations causing autism can sway parents’ decisions about vaccinating their children- putting their kids, and all their friends/schoolmates, at risk from diseases which had been all but eradicated.

The development of vaccines is one of the most important advances in the history of medicine. Indeed, a recent Parliament Postnote discussed how governments should further stimulate vaccine research (Post, 2008). However, even with increased efforts of policy makers, in recent year’s vaccination rates have declined. In many regions of the UK rates lie well below the recommended 95% uptake (Health Protection Service, 2013). One obstacle may be the influence of anti-vaccine conspiracy theories. Rather, current psychological research has shown exposure to anti-vaccine conspiracy information reduces pro-vaccination intentions (Jolley & Douglas, accepted*). Thus, whilst the decrease uptake of vaccines could be for several reasons, it highlights the contributing potential detrimental effect of conspiracy theories.

Maybe the conspiracy theorists are in the pay of Big Measles. Or perhaps they’re so wrapped up in their fantasy worlds that they’re blind not just to reality but to the potential harm of the lies they’re propagating.

Should conspiracy theory research inform public policy? | The Psychology of Conspiracy Theories.