While childhood immunization rates show the vast majority of U.S. parents support vaccination, the country is dotted with clusters of people who think the risks outweigh the benefits. Reaching the 10% who decline the measles, mumps and rubella (MMR) vaccine is a challenge for healthcare authorities and research suggests there is no easy solution.
A paper published in Pediatrics this week reports on the difficulty of communicating pro-vaccine messages. In the study, researchers from the U.S., U.K. and Australia report on how 1,759 parents responded to four messages, each of which used a different strategy to show vaccines are safe and effective. The messages ranged from Centers for Disease Control and Prevention (CDC) data on the lack of a link between vaccines and autism to a dramatic narrative about a baby who almost died from measles. None of the messages made the parents more likely to vaccinate their kids.
"If these messages were working, they should increase the intent to vaccinate. This highlights the extent to which we tend to overrate how persuasive facts and evidence are in all kinds of domains," lead study author Brendan Nyhan told NBC News. In some cases the messages had unintended effects. Parents who saw images of sick kids were more likely to express a belief in a link between vaccines and autism, while the story of a child who almost died from measles increased concerns about serious vaccine side effects.
The study is the latest evidence that health authorities must tread carefully when crafting pro-vaccine communications. Last year a study of how pro- and anti-vaccine views spread on Twitter ($TWTR) found tweets promoting immunization appear to spur a rise in negative posts. To avoid such unintended consequences the authors of the new paper in Pediatrics recommend testing how skeptics respond to a pro-vaccine message before using it widely. A message that is persuasive to an immunologist won't necessarily convince someone who holds entrenched anti-vaccine views.
As the study authors put it, "the best response to false beliefs is not necessarily correct information."