THURSDAY, Aug. 23, 2018 (HealthDay News) -- Politics weren't their only target.

New research suggests that Russian trolls and social media bots also tried to sow false information on Twitter about the supposed "dangers" of vaccines.

Researchers analyzed thousands of tweets sent between July 2014 and September 2017. They identified misleading tweets about vaccines from several accounts belonging to the same Russian trolls who interfered in the 2016 U.S. election, as well as marketing and malware bots.


"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," said study researcher David Broniatowski. He is an assistant professor in the School of Engineering and Applied Science at George Washington University in Washington, D.C.

"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," Broniatowski said in a university news release.

"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," he added.

"Content polluters" -- bot accounts that spread malware and controversial information -- shared anti-vaccination messages 75 percent more than average Twitter users, the study found.

The researchers also found that hundreds of tweets linking vaccination to contentious issues in the United States, such as racial and economic inequality, were sent by accounts linked to the Internet Research Agency, a Russian government-backed company indicted by a U.S. grand jury for its attempts to interfere in the 2016 elections in the United States.

"These trolls seem to be using vaccination as a wedge issue, promoting discord in American society," said researcher Mark Dredze, a professor of computer science at Johns Hopkins University.

"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," Dredze said.

The findings were published Aug. 23 in the American Journal of Public Health.

More information

The U.S. Department of Health and Human Services has more on vaccines.