Social media ‘bots’ and Russian trolls promoted discord and spread false information about vaccines on Twitter, suggests a new retrospective observational study in the American Journal of Public Health.
Analysing 1,793,690 tweets collected from July 2014 through September 2017, US researchers compared bots to average users’ rates of vaccine-relevant messages, and quantified the impact of known and suspected Twitter bots and trolls on amplifying polarising and anti-vaccine messages.
Compared with average users, Russian trolls, sophisticated bots and ‘content polluters’ (accounts that disseminate malware and unsolicited content) tweeted about vaccination at higher rates. Whereas content polluters posted more significantly anti-vaccine content, Russian trolls amplified both sides. Unidentifiable accounts were more polarised and anti-vaccine.
The analysis is supplemented by a qualitative study of the Russian troll-linked Twitter hashtag #VaccinateUS - designed to promote discord using vaccination as a political wedge issue – which showed its messages were more political and divisive.
Online discourse about vaccination has become weaponsied, with attempts to spread misinformation by foreign powers, using similar tactics to those used in the 2016 US elections, the study authors said.
More research is needed to determine how best to combat bot-driven online content that could impact public health, they concluded.