In making the safety of vaccines a “wedge issue” on social media, the trolls could have an impact on public health, the researchers concluded.
“By playing both sides, they erode public trust in vaccination, exposing us all to the risk of infectious diseases,” said Mark Dredze, one of the study’s authors. “Viruses don’t respect national boundaries.”
The study “Weaponized Health Communication: Twitter Bots and Russian Trolls Amplify the Vaccine Debate” was published today in the American Journal of Public Health.
Researchers from several institutions including Johns Hopkins University and the University of Maryland looked at thousands of tweets between 2014 and 2017 and compared messages about vaccines sent from regular people with those sent by bots.
They concluded that there were more tweets about vaccinations sent by sophisticated bots, trolls from Russia and “content polluters.”
“Content polluters seem to use anti-vaccine messages as bait to entice their followers to click on advertisements and links to malicious websites,” said researcher Sandra Crouse Quinn.
“Ironically, content that promotes exposure to biological viruses may also promote exposure to computer viruses.”
The Russian trolls, on the other hand, were spreading discord with false equivalency and intentionally polarizing language, the team found. And some of those trolls are linked to the same company linked to interfering in the 2016 election.
The team found more than 250 tweets related to vaccines associated with the Internet Research Agency, a company backed by the Russian government.
They found 93 percent of tweets about vaccines were posted by accounts that could not be determined to be either human users or bots.
“Apparently only the elite get ‘clean’ #vaccines,” one such tweet read.
“And what do we, normal ppl, get?!”
Posts like this, linking vaccines to socioeconomic, racial and religious divisions in American society, were associated with trolls and sophisticated bots, the team found.
“Such strategies may undermine the public health,” the study says. “Normalizing these debates may lead the public to question long-standing scientific consensus regarding vaccine efficacy.”
In recent years, outbreaks of certain diseases have cropped up nationwide and have been linked to parents’ reluctance to vaccinate their children.
For instance, an outbreak of measles that started at Disneyland in 2015 may have been linked to non-vaccinated kids, a pediatric study concluded.
For “herd immunity” to be established and keep people free of certain diseases, public health experts say that between 96 percent and 99 percent of the population should be vaccinated.