Myths stick: why public health campaigns could increase resistance to vaccination

Image credit: Pan American Health Organisation via Flickr.

Myself and a large majority of my friends are scientists. We trust in scientific consensus: we believe that climate change is man-made, that genetic modification has potential and that vaccines save lives. It is easy, as scientists, to forget that not everyone agrees and to believe that if only the topics were properly explained, anyone would come to our conclusion. But this belief is naïve and unhelpful.

Recent work by Sara Pluviano in the psychology department at University of Edinburgh has looked specifically at countering the myth that the MMR (measles, mumps and rubella) vaccine can cause autism. There is no evidence to support the link between the MMR vaccine and autism, yet it is an idea that persists. The group looked the success of different interventions  in informing the public that the MMR vaccine is safe and effective.

Volunteers were shown information about vaccines presented in three different ways: ‘myth vs fact’ sets out the myths and counters them; ‘visual’ uses tables to compare harm caused by infection and side effects of vaccines; and  ‘fear’, shows images of children infected with measles, mumps or rubella. The research then compared what the volunteers perception of the MMR vaccine before these intervention, immediately after and three days later.  None of these interventions were effective; in fact, there was a modest increase in people’s hesitance to vaccinate their children after the three days.

The research group explain this as a failure for people to update their memory with new information. This has been shown in a range of other areas: people can accept new information but still retain the misinformation they previously held. After seeing the ‘myth vs fact’ intervention people agreed more strongly with the statement MMR causes autism. This could be because the myth is repeated and therefore reinforced. Both ‘fear’ and ‘visual’ techniques had, in other circumstances, been effective in other contexts. However, in the findings from this particular study, they did not prove effective campaigns and could not override the previous knowledge.

These findings have important consequences for public health campaigns, the most notable being that repeating myths to counter them is ineffective. It also gives us, as scientists, an opportunity to reflect on what and why we believe. The data regarding the safety of vaccines is compelling and abundant and so of this we can be confident. However, we should be reminded that repetition of an idea does not mean we must accept it. Scientific engagement and education is an excellent opportunity to give people tools and the confidence to assess evidence for themselves. Perhaps encouraging  the public to think critically is more effective than simply reminding them of why they are wrong.


This article was written by Rebecca Plowman and edited by Bonnie Nicholson.

Leave a Reply

Your email address will not be published. Required fields are marked *