Maybe there should be a vaccine for stubbornness, because it sure seems tough to cure. A new study shows that when presented with four different scientifically proven arguments that vaccinations are safe, some anti-vaccination parents seemed even less inclined to innoculate their kids against measles, mumps and rubella (MMR) once they saw the evidence.
“We shouldn’t overestimate how effective facts and evidence are in convincing people to accept a claim and change their behavior,” said Brendan Nyhan, who authored the study published in Pediatrics, “but throwing facts and evidence at them isn’t likely to be the most effective approach.”
Nyhan and his colleagues surveyed almost 1,800 parents of young children after seeing one of four vaccination messages similar to those provided by the CDC. The first messages were focused on conveying the dangers of measles, mumps, and rubella: the “Disease Risk” message detailed the medical risk of contracting MMR, the “Danger Narrative” told the story of a woman whose son contracted the measles from another child and got a 106-degree fever, and the “Disease Images” showed disturbing pictures of infected children. A fourth message, “Autism Correction,” provided heavy scientific evidence that disproved the link between vaccinations and autism.
All that sounds convincing, but none of it really works. The researchers found that none of the four messages significantly increased rates of intended vaccination (they only measured whether parents intended to vaccinate, not whether they actually did) and some even provoked an anti-vaccination backlash. The least successful messages were “Disease Narrative” and “Disease Images,” which actually increased the misconception that vaccinations will have negative side effects by 6%, and looking at the photos of the sick kids increased the subjects’ perception that vaccines cause autism. Nyhan said that he thought this was because when people saw children in distress, they became preoccupied with other dangers their child could encounter.
“Disease Risks” and “Autism Correction” had slightly better results, but neither seemed to convince parents. And while “Autism Correction” proved to some parents that there’s no link between vaccines and autism, it produced a strong backlash in others that just reinforced their sense that vaccinations are a conspiracy theory. Only 45% of the already anti-vaccine parents said they would vaccinate after they saw the “Autism Correction” message, compared to 70% of the control group.
Nyhan thinks that these parents are suspicious of the scientists and that the pro-vaccine movement is trying to pull a fast one on them. “People think, ‘what are they trying to convince me?'” he explained. “The ‘don’t worry, don’t worry, everything is safe’ approach is not often effective, because they think ‘why are they trying so hard to reassure me that everything is safe?'”
The fact that none of these messages were particularly effective is a little disconcerting considering that vaccinations only work if a majority of the population is vaccinated. And Nyhan also pointed out that these diseases are more dangerous than ever, because MMR is so rare that we almost never encounter them. Regardless, it seems that the CDC has a serious PR problem, since none of their pro-vaccination messages seem to actually convince people.
“We need to test the messages we use in public health the way we test other kinds of inventions,” Nyhan said. “There isn’t a crisis now, but this is about making sure we don’t have one.”
To see which states are vaccinating their kids, check out this helpful map from Mother Jones.