JMIR Publications

ABSTRACT

Background:

Prevalence of and spread of misinformation are a concern for the exacerbation of vaccine hesitancy and a resulting reduction in vaccine intent. However, few studies have focused on how vaccine misinformation diffuses online, who is responsible for the diffusion, and the mechanisms by which that happens. In addition, researchers have rarely investigated this in non-western contexts particularly vulnerable to misinformation.

Objective:

This study aims to identify COVID-19 vaccine misinformation, assess its diffusion, and identify the key users responsible for its transmission on a Taiwanese online forum.

Methods:

The study uses data from a popular forum in Taiwan, PTT. A crawler scraped all threads on the most popular subforum from January 2021 until December 2022. After, the Chinese word for “vaccine” filtered the corpus for any threads mentioning vaccines (n=5,818). Labels of misinformation types derived from the literature were assigned by two raters, which were further collapsed into “true information” and “false information”. Diffusion breadth was assessed with a regression model. Polarity was proposed as a proxy for measuring echo chambering, the mechanism for spreading misinformation; the association of node-level properties to polarity identified key users spreading misinformation.

Results:

Misinformation content did not vary much from other contexts. For diffusion breadth, propaganda was most likely to be reposted (IRR: 2.07, P<.001) relative to true information. However, the more polar the user’s commenting behaviour, the less likely to be reposted (IRR: 0.22, P<.001), suggesting a lack of echo chambering. Nevertheless, users that were high commenters and “brokers” drove polarity and echo chambering.

Conclusions:

While the forum exhibits a resilience to echo chambering, active users and brokers contribute significantly to the polarization of the community, particularly through propaganda-style misinformation. More effort can be put into moderating these users to prevent polarisation and spread of misinformation to prevent growing vaccine hesitancy.