From bad to worse: The representation of the HPV vaccine Facebook

Anti-HPV vaccination social media messages may increase vaccine hesitancy and avoidance. This study analyzed (1) the first decade of public, HPV-vaccine related Facebook posts' characteristics, engagement, and health belief messages; (2) relationships between variables; (3) how those variables changed over time; and (4) identified and analyzed the posts with the most engagement.

The data sample consisted of 6,506 public HPV vaccine-related Facebook posts (n = 6,506) published within the first decade following the FDA's first HPV vaccine approval (June 8, 2006 - June 8, 2016). Post characteristics, engagement, and health belief model (HBM) messages were coded (Krippendorf's alpha range: 0.71-1.00).

Barriers to HPV vaccination appeared more often (47.1%) than benefits (19.8%). Regarding the tone towards the vaccine, negative was dominant (45.0%) and the average sample sentiment was negative (M = -0.15, SD = 0.851). Tone positivity was negatively correlated with barriers to HPV vaccine (r = -0.631, p < 0.0001). The post with the most engagement (11,000 reactions, 6,100 comments, and 329,000 shares displayed) was anti-HPV vaccine, and negative posts received significantly greater engagement. Over time, negative tone and barriers had a greater presence. The data showed evidence for forward momentum (Durbin-Watson values) of HPV infection susceptibility (0.004), HPV infection severity (0.426), HPV vaccine benefits (0.297), and barriers to HPV vaccination (0.226) messages, tone (0.690), and the number of reactions (1.589), comments (1.389), and shares (1.340).

Facebook posts about the HPV vaccine were mostly negative with a frequent focus on barriers to vaccination. Time effects suggest that anti-HPV vaccine posts have encouraged more anti-HPV vaccine posts. Research should continue to address the influence of time. The influence of messages that are pro-HPV vaccine, but perhaps are negative in tone, address barriers, and/or presented by individual stakeholders, should be tested inside and outside of social media channels.