Modern vaccines have saved over 150 million lives. Yet misinformation about them can still have deadly consequences. A gunman recently opened fire at the US Centers for Disease Control and Prevention headquarters, wrongly believing that the coronavirus vaccine had caused his depression.

Public health is increasingly being threatened by the spread of dangerous misinformation. In fact, there have been several recent cases of healthy unvaccinated children who died after contracting the highly contagious measles virus – including in July in Liverpool. Childhood vaccination rates in the UK are now at their lowest point in over a decade, well below the World Health Organization recommended threshold of 95% for herd immunity.

Much research shows that once exposed, people often continue to rely on falsehoods despite having seen a debunk or fact-check. Fact-checks matter, but it’s difficult to get people to engage with science and to spread corrective information across an increasingly fractured media landscape.