As long as there have been vaccines, there have been those who doubted their science and safety.

In 19th-century England, people rioted against mandatory smallpox vaccinations, citing civil rights violations. In the US, anti-vaccination groups like the Anti-Compulsory Vaccination League of Brooklyn emerged in 1894. Today, vaccine hesitancy is famously associated with movements like Make America Healthy Again, led by Health and Human Services Secretary Robert F. Kennedy Jr.

Public health advocates have long tried countering these beliefs with factual information. But researchers studying vaccine hesitant groups find that their success is limited because these groups use storytelling to spread their views effectively.

Vaccine-hesitant groups have more freedom in the stories they tell, making them appear more dynamic compared to science-driven messaging which often has to be faithful to complex realities. Facts alone aren't enough; a range of issues fuel vaccine hesitancy, including misinformation, social belonging and religious beliefs.