Anti-vaxxers Are Anti-vaxxers for One of These Four Reasons

The anti-vaccine movement is often associated with the repeatedly debunked claim that the MMR shot causes autism. However, scientists studying anti-vax posts on Facebook found that the movement doesn't stem from one fear, but rather a range of theories believed by people spanning demographics and the political spectrum.

The authors of the study published in the journal Vaccine assessed 197 Facebook users who posted anti-vaccine comments beneath a video advocating the HPV jab on the page of a local pediatric clinic. A month after the video was first shared, thousands of users posted comments over a period of eight days which the authors described as "distinctly anti-vaccine." A comment was deemed "distinctly anti-vaccine" if it was threatening—''you'll burn in hell for killing babies"—or extremist—''you have been brainwashed."

Beth Hoffman, lead author and doctoral student at the University of Pittsburgh Graduate School of Public Health, told Newsweek the team was shocked by how widely and rapidly anti-vaccination material spread on social media.

"Another surprising finding was the diversity we saw among people who posted anti-vaccination content. For example, they traversed the political spectrum from the far right to the far left."

The researchers wanted to find out what type of person would share anti-vaccine literature, and the sort of disinformation that was common.

By looking at the information the Facebook users shared about themselves, the team were able to collect demographic data including the age, gender, location, political affiliation, marital, employment and parental status, as well as the education level of the posters.

Most of the subjects were female, at 89 percent; 78 percent were parents, 29 percent were employed, and 24 percent had a post-secondary education. Of the total, 56 percent supported Donald Trump, and 11 percent supported Bernie Sanders. Although not all users shared their location, of those who did 24 were in California, nine Texas, eight Australia, and eight from Canada.

The researchers divided the theories of the posters into four categories. Those filed under "trust" were worried about personal liberties and distrusted the medical community. "Alternatives" featured people who thought remedies without scientific backing, such as homeopathy, could protect their health. One such individual thought yogurt cured HPV. The "safety" group was worried by the risks of vaccines, or that they were immoral. And those in the "conspiracy" category said the government and covert organizations were lying about public health issues, for instance that the polio virus doesn't exist and pesticides cause its symptoms, or that fluoride in water is dangerous.

In recent years, health professionals have been fighting to contain and disprove anti-vaccine sentiment online. Although people have been opposed to vaccines for one reason or another for as long as the idea of immunization existed, the rise of the internet and social media has made anti-vaccine information contagious. What's more, lies spread faster than the truth on social media, the authors wrote. Studies have shown looking at an anti-vaxxer website for just five to 10 minutes can make an individual less likely to vaccinate. And in the U.S., only 70 percent of children aged between 19 to 35 months have their recommended immunizations, with a recent spike in children being exempted for non-medical reasons.

Dr. Brian Primack, senior author of the study and director of the Center for Research on Media, Technology and Health at the University of Pittsburgh, told Newsweek parents who are still on the fence about vaccines "should talk to their pediatrician or family doctor about their concerns, especially when it comes to any information they may see on social media about vaccines."

Professor Jennifer Reich of the Sociology Department at the University of Colorado Denver, and the author of Calling the Shots: Why Parents Reject Vaccines was not involved in the research. She told Newsweek she was surprised that so many of the comments beneath the video were about infants and vaccines in general, when the HPV shot is given in the tween or teen years.

"This suggests that the posts were not actually engaging the video but rather, using it as an opportunity to post concerns about vaccines in general," she said.

William Moss, a specialist in epidemiology and immunology at Johns Hopkins Bloomberg School of Public Health, who also did not work on the research, told Newsweek: "What surprised me most was the demographic profiles of those who posted anti-vaccine material, particularly that most identified as women and parents. Also surprising was that the individuals were from 36 states and 8 countries, despite the fact that they were responding to a video posted by a single pediatric clinic in Pittsburgh."

Reich also pointed out some limitations of the study, as acknowledged by its authors.

"The study assumes that the online profiles they could view represent actual people and that these people are speaking their true beliefs. We have reason to believe that much of the rhetoric on Facebook that promotes information critical of vaccines is generated by trolls to create discord."

One study published in the American Journal of Public Health last year revealed Russian trolls and social media bots used tactics similar to those employed during the 2016 presidential election to spread misinformation about vaccines.

"Having said that," continued Reich, "the rhetoric here draws on particular social themes that are likely to create doubt for parents who encounter them. So even if they are not written by actual mothers, they are drawing on fears that are already in circulation and may work to increase doubt."

"The challenge for pediatricians and public health researchers is to communicate the safety and efficacy of vaccines in ways that are compelling to parents."

Helen Bedford, an epidemiology expert at the University College London Great Ormond Street Institute of Child Health, who was not involved in the study, told Newsweek: "The title of the study is 'It's not all about autism'—it never has been just about autism—autism as a concern is relatively recent. The public has always had questions about vaccines and indeed myths about vaccines have circulated as long as they have been in use, since the end of the 18th century."

She also argued the paper was limited because it only focused on the HPV vaccine and responses to one video developed for the purpose of the study, so is not representative of views about all vaccines, or of wider Facebook discussions.

"It does not tell us if these messages influence parents not to immunize, simply that they are there," she said.