DENVER – People who believe that vaccines cause autism find themselves in good company on Twitter, according to a new study co-written by a CU Boulder assistant professor.
Chris Vargo, an assistant professor in CU’s College of Media Communication and Information, worked with several other researchers to develop a computer algorithm that analyzed more than half a million tweets between 2009 and 2015. For the purpose of the study, the researchers looked only at tweets that mentioned both vaccines and autism spectrum disorders.
The results showed that about half of those tweets – 272,546 – contained anti-vaccine beliefs, and the authors say that overall, those types of tweets became more common during that time frame.
The anti-vaccine tweets weren’t evenly distributed, however. The research found that areas with high affluence – households making more than $200,000 a year – and areas with high numbers of new moms had increased concentrations of tweets with anti-vaccine sentiments.
Tweets suggesting that vaccines cause autism were especially prevalent in five states – California, Connecticut, Massachusetts, New York and Pennsylvania.
In Colorado, Fort Collins emerged as a hotspot for anti-vaccine views, with more than 59 percent of the tweets included in the study showing anti-vaccine sentiment. In Denver, that number was 24 percent.
“The debate online is far from over,” Vargo said. “There is still a very vocal group of people out there who are opposed to vaccines.”
The belief that vaccines contribute to autism has been prevalent for years despite a lack of scientific support. So-called “anti-vaxxers” often cite a since-retracted study from 1998 that suggested the MMR vaccine gave kids a predisposition to developmental problems. The study only examined 12 children and subsequent studies have not found a conclusive link between vaccines and autism spectrum disorders.
“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 co-author Theodore Tomeny 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 only one side of the story is being told.”
The study is published in the October issue of Social Science and Medicine .