Those opposed to vaccinating their children, commonly known as 'anti-vaxxers,' are a very stubborn bunch. Even in the face of mountains of scientific evidence about how tried-and-true vaccines are harmless, these individuals chose to stand by raw belief and hearsay. One thing, however, can still sway them. The images of children sick with the illnesses vaccines prevent, a new study has found, are powerful enough to make anti-vaxxers change their stance.

Full disclosure: this reporter finds the ani-vaxxer movement a bit absurd. Skepticism of the status quo is healthy in any society, but when one purposely puts their children and the children around them in harm's way because of a theory (one started in 1998 by a Lancet medical journal article that was quickly refuted and retracted) with little-to-no reputable evidence backing it... that's going too far.

However, we're not here today to talk about whether anti-vaxxers are right or wrong. We're here to talk about what can change their minds, and according to a study recently published in the Proceedings of the National Academy of Sciences, when facts fail, it's time to break out the pictures.

For the study, researchers tested 315 participants' views about a number of potentially controversial subjects, including their attitude towards vaccines and their willingness to vaccinate their children. They were not told the study would focus on their opinions about vaccination. (Scroll to read on...)

The participants were then divided into three groups. The first group was given literature refuting the anti-vaxxer argument -- primarily focusing on debunking the theory that vaccines cause autism.

A second group was asked to read a first-hand account from a mother whose child was infected with measles. The material came with pictures of a child with measles, a child with mumps, and an infant with rubella. The group, called the "disease risk group," also read three short warnings about the importance of vaccinating one's children.

The last group was a control group, and was asked to read about a subject unrelated to vaccinations.

Afterwards, the participants were tasked with answering questions about their past vaccine behaviors and their intention to vaccinate their children in the future.

"We found that directing people's attention to the risks posed by not getting vaccinated, like getting measles, mumps and rubella and the complications associated with those diseases, changed people's attitudes positively towards vaccination - and that was for even the most skeptical participants in the study," Zachary Horne, a researcher at the University of Illinois, said in a statement.

"Actually," he added, "the largest effect sizes were for people who were the most skeptical." (Scroll to read on...)

The reason for this, Horne and his colleagues explained, is actually very simple. At the end of the day, anti-vaxxers are not bad or even unintelligent people.

"People who fear vaccines ultimately do care about the safety of their children," he said.

The trouble is, ani-vaxxers are fixated on the supposed risk of getting a shot, such as the MMR vaccine.

"But there's also the risk of not getting the shot. You or your child could get measles," he said.

The trick then, is to expose anti-vaxxers to as much material concerning disease risk as they have already been made aware of concerning vaccination skepticism.

"Perhaps we need to direct people's attention to the other aspect of the decision," Horne said. "So there's not just one calculation in your decision whether to get a vaccination, but now there are two."

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