It’s not all about autism: The emerging landscape of anti-vaccination sentiment on Facebook

Abstract

Background: Due in part to declining vaccination rates, in 2018 over 20 states reported at least one case of measles, and over 40,000 cases have been confirmed in Europe. Antivaccine posts on social media may be facilitating anti-vaccination behaviour. This study aimed to systematically characterize (1) individuals known to publicly post antivaccination content on Facebook, (2) the information they convey, and (3) the spread of this content. Methods: Our data set consisted of 197 individuals who posted anti-vaccination comments in response to a message promoting vaccination. We systematically analysed publicly-available content using quantitative coding, descriptive analysis, social network analysis, and an in-depth qualitative assessment. The final codebook consisted of 26 codes; Cohen's κ ranged 0.71-1.0 after double-coding. Results: The majority (89%) of individuals identified as female. Among 136 individuals who divulged their location, 36 states and 8 other countries were represented. In a 2mode network of individuals and topics, modularity analysis revealed 4 distinct subgroups labelled as "trust," "alternatives," "safety," and "conspiracy." For example, a comment representative of "conspiracy" is that poliovirus does not exist and that pesticides caused clinical symptoms of polio. An example from the "alternatives" subgroup is that eating yogurt cures human papillomavirus. Deeper qualitative analysis of all 197 individuals' profiles found that these individuals also tended to post material against other health-related practices such as water fluoridation and circumcision.

Critical Evaluation of a Survey Claiming “Long-Term Adverse Outcomes from Neonatal Circumcision”*

“…The finding in H&C's Table 9 of "Reports of desired retribution against physicians performing non-therapeutic circumcision" is consistent with similar sentiments, and threats, expressed on social media, as revealed in a recent study of Facebook comments by anti-vaccination proponents, who were found to be more likely to be anti-MC and anti-water fluoridation [163]. The anti-MC and anti-vaccination movements share similar features: casting doubt on the validity of the scientific method, employment of anecdotes and "junk science," demonizing anyone who dares disagree with their beliefs, and resorting to specious arguments and twisted logic.…”

Post-marketing surveillance of adverse events following measles, mumps, rubella and varicella (MMRV) vaccine: retrospecive study in apulia region (ITALY), 2009-2017

“…For "anti-vax" and "vaccine sceptic" the vaccine safety is the topic most discussed when doubts about vaccination strategies are proposed. 6 Although international guidelines recommended that all adverse events must be detected and reported to improve product safety and management, the passive surveillance system adopted by national authorities is affected by an high risk of AEFIs underreporting, especially for not serious events. 7 For this reason, recently active surveillance and supplemental strategies are being incorporated into vaccine safety programs: these include active screening for targeted conditions of interest (e.g., hospitalization), monitoring of new data sources and real-time methodologies to detect changes in vaccine safety data in these sources.…”

The internet: A brief history based on trust

“…For instance, it is not uncommon for people to dismiss entirely a doctor's advice based on conflicting advice online; as two examples, consider the anti-vaccination movement (Brownlie & Howson, 2005) as well as the use of crowdsourced medical information sites (Bakke, 2015). A key strategy of this movement is to incite distrust in the traditional medical community through proliferation of personal stories and conspiracy theories, websites devoted to "alternative" interpretations of scientific data, and the promotion of alternative treatments, medications, and educational materials (Hoffman et al, 2019;Yiannakoulias et al, 2019). An accompanying strategy is the (mis)use of crowdsourced review forums, such as Yelp, with coordinated activities of posting negative reviews of doctors and medical institutions assessed as "pro-vaccine. "…”