Facebook and Twitter vaccine sentiment in response to measles outbreaks

Abstract

Social media posts regarding measles vaccination were classified as pro-vaccination, expressing vaccine hesitancy, uncertain, or irrelevant. Spearman correlations with Centers for Disease Control and Prevention-reported measles cases and differenced smoothed cumulative case counts over this period were reported (using time series bootstrap confidence intervals). A total of 58,078 Facebook posts and 82,993 tweets were identified from 4 January 2009 to 27 August 2016. Pro-vaccination posts were correlated with the US weekly reported cases (Facebook: Spearman correlation 0.22 (95% confidence interval: 0.09 to 0.34), Twitter: 0.21 (95% confidence interval: 0.06 to 0.34)). Vaccine-hesitant posts, however, were uncorrelated with measles cases in the United States (Facebook: 0.01 (95% confidence interval: -0.13 to 0.14), Twitter: 0.0011 (95% confidence interval: -0.12 to 0.12)). These findings may result from more consistent social media engagement by individuals expressing vaccine hesitancy, contrasted with media- or event-driven episodic interest on the part of individuals favoring current policy.

Keywords: measles; patient compliance; social media; treatment refusal; vaccination.

Figure 1

Facebook volume matching query, by stance, 2009–2016, according to classification by as described in the text. Measles cases are shown by the differenced cumulative series derived from CDC reports, as described in the text. Facebook volume and reported measles cases shown in consecutive periods of four weeks, with a final period consisting of 3 weeks. BMJ article indicates Deer, 2011. Additional details on the measles outbreaks are given in the Appendix. Source: Crimson Hexagon, CDC.

Figure 2

Tweet volume matching query, by stance , 2009–2016, according to classification by BrightView, as described in the text. Measles cases are shown by the differenced cumulative series derived from CDC reports, as described in the text. Tweet volume and reported measles cases shown in consecutive periods of four weeks, with a final period consisting of 3 weeks. Additional details on the measles outbreaks are given in the Appendix. Source: Crimson Hexagon, CDC.

Figure 3

(a) Topic wheel for posts expressing vaccine hesitancy on Facebook, 23 June 2009 to 27 August 2016, derived from Crimson Hexagon. (b) Topic wheel for non-vaccine-hesitant Facebook posts in our corpus, 23 June 2009 to 27 August 2016, derived from Crimson Hexagon. (c) Topic wheel for tweets expressing vaccine hesitancy, 23 June 2009 to 27 August 2016, derived from Crimson Hexagon. (d) Topic wheel for non-vaccine-hesitant tweets in our corpus, 23 June 2009–27 August 2016, derived from Crimson Hexagon. (*redacted specific famous celebrity’s name).

Figure 4

(a) Topic wheel for tweets expressing vaccine hesitancy during the non-outbreak period 14 September 2014 to 15 November 2014, derived from Crimson Hexagon. (b) Topic wheel for tweets in our corpus not expressing vaccine hesitancy during the non-outbreak period 14 September 2014 to 14 November 2014, derived from Crimson Hexagon. (c) Topic wheel for tweets expressing vaccine hesitancy during the outbreak period 30 November 2014 to 30 May 2015, derived from Crimson Hexagon. (d) Topic wheel for tweets in our corpus not expressing vaccine hesitancy during the outbreak period 30 November 2014–30 May 2015, derived from Crimson Hexagon. (*redacted specific famous celebrity’s name).