Effective interventions aimed at correcting COVID-19 vaccine misinformation, known as fact-checking messages, are needed to combat the mounting anti-vaccine infodemic and alleviate vaccine hesitancy.
This works investigates (a) the changes of the public's attitude toward COVID-19 vaccines over time, (b) the effectiveness of COVID-19 vaccine fact-checking information on social media engagement and attitude change, and (c) the emotion and linguistic features of COVID-19 vaccine fact-checking information ecosystem.
We collected a dataset of 12,553 COVID-19 vaccine fact-checking Facebook posts and their associated comments (N=122,362) from January 2020 - March 2022 and conducted a series of natural language processing and statistical analyses to investigate trends in public attitude toward the vaccine in COVID-19 vaccine fact-checking posts and comments, and emotional and linguistic features of the COVID-19 fact-checking information ecosystem.
The percentage of fact-checking posts relative to all COVID-19 vaccine posts peaked in May of 2020 and then steadily decreased as the pandemic progressed (r = -.92, df = 21, t = -10.94, 95% CI = [-.97, -.82], P < .001). The salience of COVID-19 vaccine entities was significantly lower in comments (M = 0.03, t = 39.28, P < .001) than in posts (M = 0.09). Third-party fact checkers have been taking a more important role with more fact-checking over time (r = .63, df = 25, t = 4.06, 95% CI = [.33, .82], P < .001). COVID-19 vaccine fact-checking posts continued to be more analytical (r = .81, df = 25, t = 6.88, 95% CI = [.62, .91], P < .001) and more confident (r = .59, df = 25, t = 3.68, 95% CI = [.27, .79], P = .001) over time. While comments did not exhibit a significant increase in confidence over time, tentativeness in comments decreased significantly (r = -.62, df = 25, t = -3.94, 95% CI = [-.81, -.31], P = .001). While hospitals receive less engagement than other information sources, the comments expressed more positive attitudinal valence in comments compared to other information sources (b = 0.06, 95% CI = [0.00, 0.12], t = 2.03, P = .043).
The percentage of fact-checking posts relative to all posts about the vaccine steadily decreased after May of 2020. As the pandemic progressed, third-party fact checkers played a larger role in posting fact-checking COVID-19 vaccine posts. COVID-19 vaccine fact-checking posts continued to be more analytical and more confident over time, reflecting increased confidence in posts. Similarly, tentativeness in comments decreased; this likewise suggests that public uncertainty diminished over time. COVID-19 fact-checking vaccine posts from hospitals yielded more positive attitudes toward vaccination than other information sources. At the same time, hospitals received less engagement than other information sources. This suggests that hospitals should invest more in generating engaging public health campaigns on social media.