Information Pathways and Voids in Critical German Online Communities During the COVID-19 Vaccination Discourse: Cross-Platform and Mixed Methods Analysis.

Background: In Germany, the messaging app Telegram (Telegram FZ-LLC) served as a tool to organize protests against public health measures during the COVID-19 pandemic. A community of diverse groups formed around these protests, which used Telegram to discuss and share views outside of the general public discourse and mainstream information ecosystem. This increasingly included conspiracy theories and extremist content, propagated by sources that opposed the mainstream positions of the government and traditional media. While the use of such sources has been thoroughly investigated, the role of mainstream information in these communities remains largely unclear. Objective: We aimed to better understand the use of mainstream information, that is, from government actors and established media outlets, within critical Telegram communities in the context of the COVID-19 pandemic in Germany. We focused on the discourse about the COVID-19 vaccination, a key public health measure. As a central element of this study, we compared the Telegram discourse with the discourse on X (formerly Twitter, X Corp) and in online news-this cross-platform analysis aimed to put the results into a broader societal context. Methods: We analyzed Telegram, X, and news data between 2019 and 2023 for popular topics related to the COVID-19 vaccination discourse. We used a mixed methods approach, including text clustering for the exploration of popular topics, a 2-stage keyword filtering scheme for multitopic classification, link sharing analysis for assessing the prevalence of mainstream information, correlation-based time series analysis for measuring the similarity of discourse dynamics, and thematic analysis to examine the reasons for sharing information. Results: We identified 5 popular vaccination-related topics that were discussed on both Telegram and X, namely death, long COVID, measures in schools, mandatory vaccination, and virus variants. On average per topic, 58% (SD 5.2%) of Telegram posts and 21% (SD 4.9%) of X posts contained an external link. Of these posts containing external links, 11%-35% of Telegram posts and 44%-60% of X posts contained a mainstream link per topic. The correlations for week-to-week changes in discourse intensity between Telegram, X, and online mainstream news ranged from no positive association (coefficient <0.2) to strong positive relationships (coefficient >0.6) per topic. Finally, the thematic analysis resulted in 5 themes describing the usage patterns of mainstream information on Telegram and X. The identified themes are observing news, news comments, directed accusations, participation, and reference in discussion (only X). Conclusions: Mainstream information sources were part of the information mix within the analyzed critical Telegram communities. However, the role and prevalence of these sources varied. We argue that differences between platforms may indicate the existence of information voids, which pose a particular challenge in managing infodemics. These insights emphasize the importance of contextualized cross-platform analyses for understanding complex information pathways and their potential for targeted crisis communication.