Source: PixabaySource: PixabayDespite the lack of evidence linking childhood vaccinations and autism and an uptick in recent outbreaks of diseases previously eradicated by vaccination, the anti-vaccination debate is still alive and well on social media platforms like Twitter according to a multi-year study from the University of Colorado Boulder.

“The debate online is far from over. There is still a very vocal group of people out there who are opposed to vaccines," said study co-author Chris Vargo, an assistant professor in the College of Media Communication and Information. "Half of the talk online that we observed about vaccines was negative."

Using a machine learning algorithm to identify tweets mentioning vaccines and autism spectrum disorders, the researchers determined that the origin of most anti-vaccination tweets are from persons living in California, Connecticut, Massachusetts, New York and Pennsylvania. Likewise, most of the authors of such tweets were predominantly affluent and/or new mothers. The anti-vaccine rhetoric, according to the study, increased in those areas between 2010 and 2015.

“Time and time again researchers have tried to substantiate this idea that there is a link between autism and vaccines but they have not been able to," said study coauthor Theodore Tomeny an autism researcher with the University of Alabama. "Unfortunately the idea is still very much out there, being promoted by a vocal minority online. That's problematic because often only one side of the story is being told."

Since the publication of a now-retracted 1998 study appearing in the Lancet, anti-vaccination proponents believe that childhood vaccines such as the MMR (measles, mumps and rubella) vaccine predisposed children to developmental disorders.

The researchers envision using the study data to better inform pediatricians of anti-vaccination sentiment in their regions and they also envision using the algorithm to help better target anti-vaccination hot-spots for the purpose of targeted public health campaigns.

"Monitoring anti-vaccination beliefs on Twitter can uncover vaccine-related concerns and misconceptions, serve as an indicator of shifts in public opinion and equip pediatricians to refute anti-vaccine arguments," the authors concluded.

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