Russian Twitter Accounts and the Partisan Polarization of Vaccine Discourse, 2015-2017

"...vaccine-related content carried by specific Twitter personas has the potential to bolster partisan polarization around vaccines, resulting in a spiraling effect on vaccine hesitancy..."

Since mid-2014, the Russian government has operated a network of social media accounts in what is widely seen as an effort to sow discord in the United States (US) political system. In an effort to avoid being tagged as suspicious by their Twitter followers, Russian Internet Research Agency (IRA) accounts have also tweeted about a wide range of nonpolitical topics, such as the safety and efficacy of vaccines. This study examines the ways in which the "personas" underlying Twitter accounts operated by the IRA discussed vaccines between 2015 and 2017. It demonstrates how anti- and pro-vaccination IRA messages were used strategically benefit the organisation's attempts to intervene in subsequent political discussions, including those surrounding the 2016 US presidential election, during which time the IRA intervened to bolster the presidential candidacy of Donald J. Trump.

The researchers analysed 2.82 million tweets published between 2015 and 2017 by 2,689 accounts identified by Twitter as being operated by the IRA. They combined unsupervised machine learning and network analysis to identify 9 distinct thematic personas based on accounts' language tendencies (i.e., accounts that consistently share the same topics). They then analysed the ways in which each discussed vaccines. In short:

1. Hard news: Only 2% of these accounts ever talked about vaccines, and only 0.04% of all their tweets were about them. When talking about vaccines, these accounts tended to provide links to news articles without expressing their own opinion.
2. Anti-Trump: Tweets seemed to be mostly pro-vaccine (38%) or neutral (52%).
3. Pro-Trump: 17% of these accounts mentioned vaccines at least once. They expressed mostly antivaccine sentiment (54% of vaccine tweets).
4. Youth talk and celebrities: Never talked about vaccines.
5. African Americans and Black Lives Matter: These alleged users exhibited a balance between antivaccine messages and provaccine ones.
6. Mixed international topics: Sentiment toward vaccines was balanced.
7. Ukraine: Did not tweet about vaccines at all.
8. Soft news: 22% of tweets mentioned vaccines at least once; stance tended to be neutral.
9. Retweets of various topics and hashtag games: Their vaccine-related content was more pro- (46%), than anti- (32%) vaccine.

Reflecting on the findings, the researchers note that, while none of the personas dedicated itself exclusively to vaccines, nor to health topics in general, it is of potential importance for public health to discover that the pro-Trump personas tended to oppose vaccines, while the anti-Trump ones did not. Others offered a balanced valence, talked about vaccines neutrally, or did not tweet about vaccines.

The worry is that: "The increase in partisan polarization could result in an increase in the number of conservatives who make their judgment of vaccines' safety and necessity not based on the science but based on their political disposition and their perception of how the topic aligns with their support for a political leader. Such a phenomenon could be further fueled by misinformation that distorts credible scientific evidence,...especially in social media and online sources where antivaccination messages are more common than in mainstream media. This, in turn, could increase vaccination hesitancy."