Some Twitter accounts spreading vaccination myths are actually bots and others are trolls who don't believe their message, a new analysis has found. Malware operators and spammers have seized on anti-vaccination messages to promote links. Meanwhile, something even stranger is emerging from the famed Russian bot farms, who are pushing both sides of the vaccine conflict on social media.

The involvement of Twitter bots and other fake social media accounts in the 2016 election has been intensively discussed. George Washington University's Dr David Broniatowski studied 1.7 million tweets from July 2014 to September 2017 to see if there were similar attacks on science. He found those coming from accounts shown to be controlled by Russian government trolls were ardently promoting the hashtag #VaccinateUS. Others with illicit commercial agendas also used the issue.

"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,” Broniatowski said in a statement. “It turns out that many anti-vaccine tweets come from accounts whose provenance is unclear... 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.”

Some bots, known as “content polluters”, exist to promote websites that spread computer viruses or spam advertising. Broiniatowski reports in the American Journal of Public Health that these accounts promote anti-vaccination myths 75 percent more than the Twitter average. Those that appear to be possible bots but are too sophisticated to identify definitively are even more anti-vaccine.

"Content polluters seem to use anti-vaccine messages as bait to entice their followers to click on advertisements and links to malicious websites,” said co-author Professor Sandra Quinn of the University of Maryland. “Ironically, content that promotes exposure to biological viruses may also promote exposure to computer viruses."

Rather than having an anti-vaccination agenda, malware operators are apparently seeking messages that attract those who are both passionate and gullible enough to click on suspicious-looking links. Some anti-vaxxers fit that description, and may also lack (computer) virus protection. In the process, content polluters magnify the anti-vaccine message to undecided parents.

The accounts Broniatowski traced to Russian government influence are different, posting an even mix of pro- and anti-vaccination messages to #VaccinateUS. Despite exaggerating the anti-vaxxer side's size, this looks at first like wasted effort.

Although these accounts walk both sides of the street, the authors found they all favored aggressive and polarizing language. They also liked linking their positions to conspiracy theories about the American government and hot-button topics in US politics, such as racial divisions.

"These trolls seem to be using vaccination as a wedge issue, promoting discord in American society," said senior author Professor Mark Dredze of Johns Hopkins University. Apparently, the Russian government thinks online spaces discussing controversial issues aren't nasty enough on their own.

The cost is not just to civility and democracy. “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. 

Russia probably isn't unhappy that their enemy Ukraine has had more measles cases this year than the rest of Europe combined. Nevertheless, with Russia experiencing 1,400 cases of the disease in six months, including some deaths, their meddling is not without cost to themselves.

Whether Twitterbots changed the outcome of the 2016 election may never be settled, but that they are harming us is now beyond doubt.