Social Media and Vaccine Hesitancy

"Understanding the threat posed by anti-vaccination efforts on social media is critically important with the forth coming need for world wide COVID-19 vaccination programs."

Studies from the early 2000s to the present demonstrate that large proportions of vaccine-related content on popular social media sites have an anti-vaccination stance - in part due to the lack of any barrier to entry, which allows fringe groups to broadcast their messages. The possible effect of social media on vaccine hesitancy is compounded by an additional factor: the intentional spread of disinformation (in addition to misinformation). Research has shown that Russian bots and troll farms, in conjunction with Russia's foreign broadcast network RT, have pushed anti-vaccination messages on social media as part of a broader effort to strategically undermine public health in both the developed and developing world. This study evaluates the effect of social media and online foreign disinformation campaigns on vaccination rates and attitudes towards vaccine safety.

The study draws on the '5-As' taxonomy to describe the following dimensions of vaccine uptake: access, affordability, awareness, acceptance, and activation. Misinformation by vaccine-hesitant groups on social media about the safety of vaccines explicitly targets acceptance. In addition, activation is defined as attempts to actively remind individuals and prod them into getting vaccines, and foreign disinformation attacks this directly by encouraging the opposite. The dimensions of access, affordability, and awareness are addressed with a suite of control variables in the study, which uses a cross-country regression framework.

The researchers operationalised social media usage in 2 dimensions: (i) the use of it by the public to organise action (using Digital Society Project (DSP) indicators) and (ii) the level of negatively oriented discourse about vaccines on social media (using a data set of all geocoded tweets in the world from 2018-2019). In addition, they independently measured the level of foreign-sourced coordinated disinformation operations on social media in 2 ways: (i) polls of the proportion of the public per country who feel vaccines are unsafe (using Wellcome Global Monitor indicators for 137 countries) and (ii) annual data from the World Health Organization (WHO) of actual vaccination rates for the 10 most commonly reported vaccine doses between 2008 and 2018 for 166 countries.

Analysis of all the data revealed that the prevalence of foreign disinformation activity was "highly statistically and substantively significant" in predicting a drop in average vaccination rates. Specifically, a 1-point shift upwards in the 5-point disinformation scale is associated with a 2-percentage point drop in annual vaccination coverage and a cumulative drop of 12 percentage points across the decade. Furthermore, the substantive effect of foreign disinformation is to increase the number of negative vaccine tweets by 15% for the median country.

In addition, a belief that vaccines are inherently unsafe was associated with organisation of action/resistance on social media, and the more organisation on social media, the greater the level of belief that vaccines are unsafe. (This particular indicator (the v2smorgavgact variable from the DSP dataset) regarding social media usage for organisation asks: "How often do average people use social media to organise offline political action of any kind?" on a 5-point Likert scale ranging from "never or almost never" to "regularly".)

Arguing that these findings are "especially salient in the context of the COVID-19 pandemic," the researchers suggest that public outreach and education campaigns to prepare for the eventual deployment of a vaccine are necessary but will not be sufficient by themselves to counter the tide of mistrust. Thus, they recommend:

• Governments should mandate that social media companies are responsible for taking down anti-vaccination content, whatever its source - This means reconciling the principles of free speech with the policing of social media for "damaging falsehoods".
• Foreign disinformation campaigns should be addressed at their source - "[G]iven the global nature of the COVID-19 crisis and the fact that pushing anti-vaccination propaganda will tangibly cause civilian deaths around the world - and in Russia - there is a chance that, with sufficient pressure and incentivisation, diplomacy could produce a ceasefire of sorts with regard to this specific genre of disinformation."

In conclusion, the researchers urge policymakers "to take the time before a COVID-19 vaccine is available for mass distribution as an opportunity for action against social media factors contributing to vaccine hesitancy."