IT is the fear that many parents commonly have, and one which the medical world has struggled to defeat – that vaccines such as the measles, mumps and rubella jab can damage children.

Now a new study involving Scottish researchers has shown that some of the pro-vaccine messages issued by health professionals can actually boost people’s belief that measles, mumps and rubella (MMR) and other vaccines are damaging.

Edinburgh University’s team joined with Italian researchers to discover that current strategies for correcting misinformation about the dangers of vaccinations have the opposite effect and reinforce ill-founded beliefs.

Presenting scientific facts to disprove misconceptions was found to actually strengthen unfounded opinions, such as that the MMR vaccine causes autism.

Similarly, showing images which suggest unvaccinated children can suffer from disease inspired the strongest belief that vaccines had harmful side effects.

The survey carried out in Scotland and Italy measured attitudes towards popular misconceptions about the MMR vaccine and asked them whether they would give the vaccine to their child. The participants were then divided and presented with different approaches to combat misinformation about vaccines.

Countering false information in ways that repeat it appears to amplify and spread the misconception, making it familiar and therefore more acceptable, university researchers said.

One group was shown a leaflet that confronted vaccine myths with facts. The second group was given a series of tables comparing potential problems caused by measles, mumps and rubella with potential side effects of the MMR vaccine.

A third group was shown images of children suffering from measles, mumps and rubella. The fourth and final group acted as a control and was given unrelated reading material.

After these interventions, participants took the survey again to see if their attitudes had changed. A week later, they took it a third time to see if their attitudes had changed.

The report, Misinformation lingers in memory: Failure of three pro-vaccination strategies, states: “Beliefs in the autism/vaccines link and in vaccines’ side effects, along with intention to vaccinate a future child, were evaluated both immediately after the correction intervention and after a seven-day delay to reveal possible backfire effects.

“Results show that existing strategies to correct vaccine misinformation are ineffective and often backfire, resulting in the unintended opposite effect, reinforcing ill-founded beliefs about vaccination and reducing intentions to vaccinate.”

The report added: “The exposure to fear appeals through images of sick children led to more increased misperceptions about vaccines causing autism. Moreover, this corrective strategy induced the strongest beliefs in vaccines’ side effects, highlighting the negative consequences of using loss-framed messages and fear appeals to promote preventive health behaviours.”

The researchers found that all of the strategies were counter-productive. Belief in vaccine myths were strengthened and the likelihood of vaccinating children lessened. This effect only increased over time.

The findings suggest that public health campaigns need more testing, according to the researchers.

They recommend a variety of simultaneous and frequent interventions, as opposed to a singular campaign. Experts also suggested addressing other barriers that impede vaccine uptake, such as ease of access and cost.

The report stated: “Ideally, corrective strategies should be directed at the precise factors that may influence vaccination decision-making and impede vaccine uptake, which include, over and beyond strong attitudes against vaccines, social norms pushing individuals to conform to the majority’s behaviour, standards for vaccine uptake in a specific population, and structural barriers to vaccination such as potential financial costs of vaccines and their ease of access.

“Successful interventions should therefore be targeted to differently ‘driven’ vaccine-hesitant individuals. For instance, when people do not vaccinate because they lack confidence in vaccines, corrective strategies should dispel vaccination myths, or when people do not vaccinate because perceived risks outweigh benefits, interventions should emphasise the social benefit deriving from vaccination and add incentives.”