Social Media Behavior Is Associated with Vaccine Hesitancy

"...results should help researchers and policymakers understand online communities associated with vaccine hesitancy and inform solutions for encouraging vaccine uptake."

Past research has linked misinformation exposure to vaccine hesitancy, and anti-vaccination viewpoints have been spreading rapidly on social media platforms. Thus, understanding how vaccine hesitancy relates to online behaviour is can support efforts to combat disease outbreaks. This study combined survey data with social media data to look at how real-world social media behaviour is associated with beliefs about vaccination.

Specifically, the researchers combined survey data measuring attitudes toward the COVID-19 vaccine with Twitter data in two studies. Most of the data were collected around the summer of 2021:

• For Study 1 (n = 464 Twitter handles), the researchers collected a roughly politically balanced sample of liberals and conservatives from the United Kingdom (UK) and the United States (US), along with a sample of participants who specifically reported being vaccine hesitant. The study found that following the accounts of US Republican politicians or hyper-partisan/low-quality news sites was associated with lower confidence in the COVID-19 vaccine - even when controlling for key demographics such as self-reported political ideology and education. US right-wing influencers had followers with the lowest confidence in the vaccine. Network analysis revealed that participants who were low and high in vaccine confidence separated into two distinct communities ("echo chambers"), and centrality in the more right-wing community was associated with vaccine hesitancy in the US, but not in the UK. (Distinctions between types of conservatism in the US and the UK may explain these differential findings.)
• Study 2 recruited a convenience sample (n = 1,600) of participants via a web app called "Have I Shared Fake News". Since this was a convenience sample, it was more left-leaning and contained more vaccine-confident participants. This study found that one's likelihood of not getting the vaccine was associated with both consuming and spreading low-quality news. These results were similar when looking at both more private forms of engagement (favoriting news websites on Twitter) and more public forms of social media sharing (retweeting), which were highly correlated with each other.

Together, these studies show that vaccine hesitancy is associated with following, sharing, and interacting with low-quality information online, as well as centrality within a conservative-leaning online community in the US. These results illustrate the potential challenges of encouraging vaccine uptake in a polarised social media environment, since accurate messages about the vaccine may not be seen by those who need it most unless they come from trusted influencers in their networks.

Nonetheless, researchers and policymakers could perhaps use the results to understand and help create solutions for vaccine hesitancy. For example, targeted messages from figures trusted by people in communities associated with low vaccine confidence, interventions that protect against susceptibility to misinformation, or algorithmic solutions that improve the overall quality of news presented to people on social media may be useful for improving vaccine confidence.

This work is correlational, so further research should follow up on this study by testing the causal effects of exposure to certain information sources on vaccine attitudes through lab and field experiments, network interventions that manipulate the structure of one's network, or network modeling approaches.