Bots and Russian trolls stoked vaccine debate on Twitter, study finds
Social media bots and Russian trolls spread false information and promoted discord about vaccines on Twitter, according to a study.
The research, led by the George Washington University in Washington DC, found that using tactics similar to those seen during the 2016 presidential election, these Twitter accounts entered into vaccine debates months before election season was under way.
Experts suggested the trolls were using vaccination as a “wedge issue” to promote discord in American society.
David Broniatowski, an assistant professor at the School of Engineering and Applied Science, said: “The vast majority of Americans believe vaccines are safe and effective, but looking at Twitter gives the impression that there is a lot of debate.
“It turns out that many anti-vaccine tweets come from accounts whose provenance is unclear.
“These might be bots, human users or ‘cyborgs’ – hacked accounts that are sometimes taken over by bots.
“Although it’s impossible to know exactly how many tweets were generated by bots and trolls, our findings suggest that a significant portion of the online discourse about vaccines may be generated by malicious actors with a range of hidden agendas.”
The study, published in the American Journal of Public Health, saw researchers examine thousands of tweets sent between July 2014 and September 2017.
They discovered several accounts – now known to belong to the same Russian trolls thought to have interfered in the US election – as well as marketing and malware bots, tweeted about vaccines and skewed online health communications.
For example, the researchers found that “content polluters” – bot accounts that distribute malware, unsolicited commercial content and disruptive materials – shared anti-vaccination messages 75% more than average Twitter users.
Meanwhile, they found that Russian trolls and more sophisticated bot accounts used a different tactic – posting equal amounts of pro- and anti-vaccination tweets.
Researchers reviewed more than 250 tweets about vaccination sent by accounts linked to the Internet Research Agency, a Russian government-backed company recently indicted by a US grand jury because of its alleged attempts to interfere in the 2016 elections.
They found the tweets used polarising language linking vaccination to controversial issues in American society, such as racial and economic disparities.
Researchers from Johns Hopkins University in Baltimore, Maryland, and the University of Maryland also took part in the study.
Mark Dredze, associate professor of computer science at Johns Hopkins, said: “These trolls seem to be using vaccination as a wedge issue, promoting discord in American society.
“However, by playing both sides, they erode public trust in vaccination, exposing us all to the risk of infectious diseases.
“Viruses don’t respect national boundaries.”