We are ineffective in communicating about vaccines

Rhett Krawit is a Californian 7-year-old kid. He survived leukaemia after a fight lasted three-and-half years that left his immune system highly compromised. He wants to go to school and he has any right to do so, but he cannot do it safely. Rhett cannot be vaccinated because his immune system is still rebuilding and the presence of unvaccinated children exposes him to diseases like measles and chicken pox, which could be lethal for him. An actual risk, since in almost one fourth of Californian schools the herd immunity has been lost because of vaccine hesitancy and refusal.

Rhett’s story is a clear example of the social responsibility aspect of vaccination and should give everybody food for thought about communication tools and strategies on such a delicate issue.

While vaccines’ usefulness is unquestionable for science, why does a rising number of parents refuse to vaccinate their children, exposing them to the avoidable risk of serious infections that still kills 2.5 million children every year in developing countries and creating a collective risk for many other citizens?

At first, it is important to note that those that radically oppose vaccines are a small social minority, as they represent 1-2 percent of the whole population in Western countries. On the other hand, almost 80 percent of citizens approves vaccination, while a bit less than 20 percent of persons display the so-called vaccine hesitancy attitude. Their numbers are dramatically rising, anyway, as a consequence of several misunderstandings and propagandas.

Mistrust and scepticism towards vaccinations are mainly due to psychological reasons, the first being the natural human dislike for risk, together with the tendency to get driven more by suspects than by evidences, and to entrust friends and relatives more than experts. Hearing about possible collateral damages following a treatment is a factor that may play a relevant role in the choice about vaccines, especially if this information come from a trusted source – regardless from its competency – and involves possible neurological adverse effects like autism.

How to talk with these hesitant parents, who often are well-educated persons? What are the best communication strategies to support vaccinations in order to persuade the uncertain ones? Such a topic has been addressed experimentally and there are some interesting results to be considered.

Last year, a study from the cognitive scientist Brendan Nyhan, published on Paediatrics, proved the inadequacy of public communication on vaccines when it is focused on tackling misinformation. A survey experiment was conducted with 1,759 parents located in the United States, who were randomly divided into four groups that received different forms of communication aimed to show the efficacy of MMR vaccine. None of the interventions increased parental intent to vaccinate a future child, even if misperceptions that vaccines cause autism were successfully reduced. Also, images of sick children increased expressed belief in a vaccine/autism link and a dramatic narrative about an infant in danger increased self-reported belief in serious vaccine side effects. Such a study could be criticised for its participants were aware of being in a constructed situation. However, its results have been obtained in other ways too, and confirmed that the most entrusted persons for parents are those more closely related, or the doctors who take cares of the patients.

Nyhan’s results have been partially confirmed by another study, published on PNAS. Direct attempt to undercut vaccination myths – like the MMR/autism link – did not make people change their ideas about vaccines. However, highlighting factual information about the dangers of certain diseases by showing pictures of children with measles, mumps or rubella, may positively impact people’s attitudes to vaccination. The authors of the study thus conclude that communication should focus more on the risks unvaccinated children are exposed to, than on vaccines’ safety.

A renewed communicative effort based on the aforementioned researches is therefore needed. We have to do that for our children and for those that cannot directly benefit from vaccines, like Rhett Krawitt.

Prof. Alberto Mantovani, Humanitas University, Milan

Prof. Gilberto Corbellini, Sapienza Università di Roma