Scientific researchers say Russian social-media trolls who spread discord before the 2016 U.S. presidential election may also have played an unintended role in a developing global health crisis.
They say the trolls may have contributed to the 2018 outbreak of measles in Europe that killed 72 people and infected more than 82,000 -- mostly in Eastern and Southeastern European countries known to have been targeted by Russia-based disinformation campaigns.
Experts in the United States and Europe are now working on ways to gauge the impact that Russian troll and bot campaigns have had on the spread of the disease by distributing medical misinformation and raising public doubts about vaccinations.
Studies have already documented how cybercampaigns by the Internet Research Agency -- a St. Petersburg "troll farm" that has been accused of meddling in the U.S. 2016 presidential election -- artificially bolstered debate on social media about vaccines since 2014 in a way that eroded public trust in vaccinations.
Now, the World Health Organization (WHO) is warning that "vaccination hesitancy" has become one of the top threats to global health.
It notes a 30 percent rise in measles globally and a resurgence of measles in countries that had once been close to eradicating the disease.
New efforts are now being launched by researchers in the United States and Europe to understand what they describe as "an incredibly complex" issue -- people opting out of available vaccinations for themselves or their children.
At Duke University in North Carolina, a center for scientific health data called The Forge is working to understand and respond to medical misinformation on the Internet.
Forge director Robert Califf, a former commissioner of the U.S. Food and Drug Administration, has said that medical misinformation may be "the issue of our times that demands top priority."
He said combating misinformation campaigns about vaccines had become more complex now that research is demonstrating that a large amount of the social-media posts represent what he called "state-sponsored cyberwarfare, particularly from Russia."
Katharina Kieslich, a political scientist at the University of Vienna, has written that "vaccination hesitancy might be explained from a political-science perspective."
Kieslich says the pervasiveness of anti-vaccination arguments ensures that challenges will remain for policymakers and health workers trying to reach "citizens who are skeptical of vaccines."
'Negative Misinformation Online'
WHO vaccine specialist Katrine Habersaat tells RFE/RL that misinformation is just one factor behind a recent decline of vaccination coverage in Eastern and Southeastern European countries where there has been a resurgence of measles.
She says other factors include complacency about the threat of the disease, the convenience of vaccination services, and confidence in health workers who carry out vaccination campaigns.
In Ukraine, the country worst hit by the 2018 measles epidemic, vaccination services and supplies were also greatly reduced in 2015 and 2016 as fighting intensified between government forces and pro-Russia separatists in the east of the country.
"We actually don't know enough about the influence of misinformation available online upon vaccination intentions and behaviors," Habersaat says. "What we do know is that there is an element of echo chambers in this."
"We may never know for sure, but I hope there will be more studies exploring this so we know how much we should fear or work against negative misinformation online," she says.
Toward that goal, Habersaat says the WHO's European regional office recently entered a "strategic relationship" with Russia's Health Ministry. They are working together with researchers in Germany to develop a framework on how to study vaccination hesitancy in the context of Russian and Eastern European culture. The results of that study are expected in mid-2020.
If applicable, Habersaat says, that framework would be applied to WHO's research in other countries where vaccination coverage has dropped and measles has become resurgent -- including Ukraine, Georgia, Serbia, Romania, Moldova, Kazakhstan, and Kyrgyzstan.
"In countries like Pakistan and Afghanistan, there are many misperceptions," Habersaat explains. "A lot of misinformation is leading parents to make decisions not to protect their children against dangerous diseases."
In Europe, vaccination coverage is high but there are specific "pockets" of population groups in all countries that have lowered coverage, she notes.
"Over the years, the number of people in those pockets that are not protected from the disease grows," she says. "At some point, there are enough to spread the disease. Then somebody comes by with measles and, poof, it spreads easily because there are enough people to transmit and it's difficult to control."
Data published by the WHO at the beginning of February confirm that Eastern and Southeastern Europe bore the brunt of the 2018 measles epidemic.
Ukraine had more than 53,200 confirmed cases of measles and 15 deaths during 2018. Serbia, Russia, Georgia, and Romania were also among the worst-hit countries -- collectively accounting for another 8,400 cases of measles, including 40 deaths.
WHO registered 22 deaths from measles in Romania last year, 14 in Serbia, three in Georgia, and one in Russia.
Russian Troll Campaign
David Broniatowski, a professor at George Washington University in the U.S. capital, has documented how trolls at the Internet Research Agency have amplified the vaccine debate in the United States and "eroded public consensus on vaccination" since 2014.
Broniatowski tells RFE/RL he hasn't seen any evidence that Russia has tried to weaken Western democracies by persuading people to stop vaccinating. Rather, known trolls masqueraded as legitimate users on social media and debated vaccines as part of their strategy to promote political polarization.
"It's a known strategy to infiltrate an interest group around a particular issue or topic and then slowly try to introduce new things into that discourse," he explains.
After "getting access to a vulnerable subgroup and getting followers from that subgroup" on social media, Broniatowski says, the Russian trolls would get their followers to retweet messages about other issues that are in line with the Kremlin's agenda.
They'd also retweet messages from known anti-vaccination accounts in order to gain credibility after infiltrating an anti-vaccination group.
By giving "equal time" to both pro- and anti-vaccination arguments, Broniatowski says Russian trolls and bots disproportionally helped legitimize and spread the dubious arguments of vaccine skeptics. "What we saw was the use by these Russian troll accounts of these hot-button issues like race relations and freedom of choice," he says.
One anti-vaccination tweet by a confirmed Russian troll account declared that "mandatory #vaccines infringe on constitutionally protected religious freedoms." Another played up the idea that the U.S. government cannot be trusted by asking, "Did you know there was a secret government database of #vaccine-damaged children?"
Broniatowski says other Russian troll tweets bolstered distrust in pharmaceutical companies and promoted "vaccine complacency" with the idea that vaccines are unnecessary because they target diseases that are relatively harmless.
Other Russian trolls played on fears by posting medical misinformation like "Natural infection almost always causes better immunity than #vaccines," and "Did you know vaccines cause autism?"