Evidence map›Paper›PMID 42054302›Full record

ArticlePloS one2026

Auditing the impact of social media's policy shift on anti-vaccine discourse: A large language model-driven empirical study.

Yufei Li, Tianhao Chen, Yanjie Zhao, Wei Ke, Patrick Pang, Dana McKay, Shanton Chang, Nancy Baxter

Abstract read
In one paragraph

Article in PloS one, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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0citing papers in PubMed
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1 · What the graph read from it

What it found

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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

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3 · Its place in the literature

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4 · The record

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5 · Who and what money

Authors and funding

8 authors.

Yufei LiFaculty of Applied Sciences, Macao Polytechnic University, Macao SAR, China.
Tianhao ChenFaculty of Applied Sciences, Macao Polytechnic University, Macao SAR, China.
Yanjie ZhaoBeijing Key Laboratory of Mental Disorders, National Clinical Research Center for Mental Disorders & National Center for Mental Disorders, Beijing Anding Hospital, Capital Medical University, Beijing, China.
Wei KeFaculty of Applied Sciences, Macao Polytechnic University, Macao SAR, China.
Patrick PangFaculty of Applied Sciences, Macao Polytechnic University, Macao SAR, China.ORCID https://orcid.org/0000-0002-8820-5443
Dana McKaySchool of Computing Technologies, RMIT University, Melbourne, Australia.ORCID https://orcid.org/0000-0001-7522-1842
Shanton ChangSchool of Computing and Information Systems, The University of Melbourne, Melbourne, Australia.
Nancy BaxterFaculty of Medicine and Health, The University of Sydney, Sydney, Australia.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

The sudden termination of X's (formerly Twitter) misinformation policy on November 23, 2022, provides an opportunity to assess the effects of lifting content moderation restrictions on vaccine-related discourse. This study examines changes in the prevalence, thematic composition, and engagement of anti-vaccine discourse following X's policy shift, analyzing tweets from a seven-day period before and after the policy termination (November 16-30, 2022), excluding the announcement date itself from regression analyses. Using GPT-4o for stance classification, thematic categorization, and stance consistency assessment, with validation through external benchmarks and cross-annotator agreement, we find that anti-vaccine tweets increased significantly post-policy (OR = 1.60, 95% CI: 1.50-1.72), particularly via retweets, suggesting content amplification. Sensitivity analyses excluding highly retweeted content revealed that the policy change was also associated with increased creation of new anti-vaccine content. Thematically, health concerns over vaccination became more prominent, while conspiracy-related and anti-mandate narratives declined in relative prevalence. Stance consistency in quote tweets increased, indicating reinforced ideological alignment in anti-vaccine discourse. These results suggest that content moderation policies may constrain both the volume and amplification of anti-vaccine content, with policy removal associated with rapid shifts in discourse patterns.

Indexed as

Health PolicySocial MediaVaccinationHumansLarge Language Models

Identifiers

PMID42054302
PMCPMC13127958

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LicenceCC BY
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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.