When people dramatically flip on their formerly staunch ideologies, it’s usually because they have become disillusioned with once-respected figures, “or because cognitive dissonance has been stretched to a breaking point”, says Pierre.

Both Greene and Johnson re-evaluated their anti-vax stance when once-trusted communities started veering from plausible-seeming medical concerns into what some observers call “the conspiracy singularity”, a worldview where ideas about vaccine harm collide with conspiracies like Pizzagate and lizard people.

However, dramatic pivots like Greene’s and Johnson’s “tend to be the exception rather than the rule”, says Pierre. Conspiratorial excesses are unlikely to alienate every believer. “On the contrary, cognitive dissonance, the tension that arises when our beliefs butt up against reality, is typically resolved by digging our heels in even deeper,” says Pierre.

Still, some researchers believe personal stories, like Johnson’s and Greene’s, are more persuasive than facts alone. To convince vaccine deniers, “scientific facts should be contextualized and made relatable to be understood as elements of a human experience”, write the authors of one 2021 report.


https://www.theguardian.com/global/2025/feb/27/how-anti-vax-parents-changed-their-minds