title: The Measles Vaccination Narrative in Twitter: A Quantitative Analysis.
abstract: BACKGROUND
  The emergence of social media is providing an alternative avenue for information exchange and opinion formation on health-related issues. Collective discourse in such media leads to the formation of a complex narrative, conveying public views and perceptions.
  
  
  OBJECTIVE
  This paper presents a study of Twitter narrative regarding vaccination in the aftermath of the 2015 measles outbreak, both in terms of its cyber and physical characteristics. We aimed to contribute to the analysis of the data, as well as presenting a quantitative interdisciplinary approach to analyze such open-source data in the context of health narratives.
  
  
  METHODS
  We collected 669,136 tweets referring to vaccination from February 1 to March 9, 2015. These tweets were analyzed to identify key terms, connections among such terms, retweet patterns, the structure of the narrative, and connections to the geographical space.
  
  
  RESULTS
  The data analysis captures the anatomy of the themes and relations that make up the discussion about vaccination in Twitter. The results highlight the higher impact of stories contributed by news organizations compared to direct tweets by health organizations in communicating health-related information. They also capture the structure of the antivaccination narrative and its terms of reference. Analysis also revealed the relationship between community engagement in Twitter and state policies regarding child vaccination. Residents of Vermont and Oregon, the two states with the highest rates of non-medical exemption from school-entry vaccines nationwide, are leading the social media discussion in terms of participation.
  
  
  CONCLUSIONS
  The interdisciplinary study of health-related debates in social media across the cyber-physical debate nexus leads to a greater understanding of public concerns, views, and responses to health-related issues. Further coalescing such capabilities shows promise towards advancing health communication, thus supporting the design of more effective strategies that take into account the complex and evolving public views of health issues.
authors.affiliation: Center for Geospatial Intelligence George Mason University Fairfax, VA United States.
authors.forename: Jacek
authors.identifier: 0000-0001-9542-2190
authors.initials: J
authors.lastname: Radzikowski
authors.affiliation: Center for Geospatial Intelligence Department of Geography and Geoinformation Science George Mason University Fairfax, VA United States.
authors.forename: Anthony
authors.identifier: 0000-0002-8165-0667
authors.initials: A
authors.lastname: Stefanidis
authors.affiliation: Department of Global and Community Health George Mason University Fairfax, VA United States.
authors.forename: Kathryn H
authors.identifier: 0000-0002-4198-6246
authors.initials: KH
authors.lastname: Jacobsen
authors.affiliation: Center for Geospatial Intelligence Department of Geography and Geoinformation Science George Mason University Fairfax, VA United States.
authors.forename: Arie
authors.identifier: 0000-0002-8470-9273
authors.initials: A
authors.lastname: Croitoru
authors.affiliation: Department of Computational and Data Sciences George Mason University Fairfax, VA United States.
authors.forename: Andrew
authors.identifier: 0000-0002-5034-6654
authors.initials: A
authors.lastname: Crooks
authors.affiliation: Department of Geography and Geoinformation Science George Mason University Fairfax, VA United States.
authors.forename: Paul L
authors.identifier: 0000-0003-3627-9739
authors.initials: PL
authors.lastname: Delamater
keywords: GIS (geographic information systems); data analysis; geographic characteristics; health informatics; health narrative; social media