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Sunday, November 17, 2019

Antivax Facebook Ads

In The Politics of Autism, I look at the discredited notion that vaccines cause autism.  TwitterFacebook, and other social media platforms have helped spread this dangerous myth.

In 2018, Facebook introduced Ad Archive as a platform to improve transparency in advertisements related to politics and “issues of national importance.” Vaccine-related Facebook advertising is publicly available for the first time. After measles outbreaks in the US brought renewed attention to the possible role of Facebook advertising in the spread of vaccine-related misinformation, Facebook announced steps to limit vaccine-related misinformation. This study serves as a baseline of advertising before new policies went into effect.

Using the keyword ‘vaccine’, we searched Ad Archive on December 13, 2018 and again on February 22, 2019. We exported data for 505 advertisements. A team of annotators sorted advertisements by content: pro-vaccine, anti-vaccine, not relevant. We also conducted a thematic analysis of major advertising themes. We ran Mann-Whitney U tests to compare ad performance metrics.

309 advertisements were included in analysis with 163 (53%) pro-vaccine advertisements and 145 (47%) anti-vaccine advertisements. Despite a similar number of advertisements, the median number of ads per buyer was significantly higher for anti-vaccine ads. First time buyers are less likely to complete disclosure information and risk ad removal. Thematically, anti-vaccine advertising messages are relatively uniform and emphasize vaccine harms (55%). In contrast, pro-vaccine advertisements come from a diverse set of buyers (83 unique) with varied goals including promoting vaccination (49%), vaccine related philanthropy (15%), and vaccine related policy (14%).

A small set of anti-vaccine advertisement buyers have leveraged Facebook advertisements to reach targeted audiences. By deeming all vaccine-related content an issue of “national importance,” Facebook has further the politicized vaccines. The implementation of a blanket disclosure policy also limits which ads can successfully run on Facebook. Improving transparency and limiting misinformation should not be separate goals. Public health communication efforts should consider the potential impact on Facebook users’ vaccine attitudes and behaviors.

From the article:
One of the ways Ad Archive aims to increase transparency is by identifying and labeling advertisement buyers. Among antivaccine advertising buyers, two were responsible for a majority (54%) of content: World Mercury Project (n = 47) and an individual buying for the group Stop Mandatory Vaccination (n = 36). World Mercury Project (WMP) and the closely aligned Children’s Health Defense (CHD) are part of an advocacy group chaired by a political celebrity spokesperson, [Robert F. Kennedy, Jr.] largely centered on the belief that vaccines are harmful and are contributing to an ‘‘epidemic of childhood chronic illness” [33]. While Ad Archive lists WMP/CHD with 90 ads, only 47 appeared in our dataset, suggesting that not all advertisements were vaccine-related, or could be identified with our search parameters. Content was consistent under both WMP and CHD labels and included a mixture of newsletters, video advertisements, and endorsements for books, products, and seminars. Most advertisements (85.1%) linked back to the group’s webpages. Two ads linked directly to, a fundraising platform, with an appeal to support the group and related legal fees. 
The group, Stop Mandatory Vaccination (SMV), is run by a California-based activist [Larry Cook] who utilizes crowdfunding to post these advertisements and pay for personal expenses [34]. Ad Archive lists 52 ads for SMV; our search parameters produced 36 (72%) of these. Many advertisements featured stories of infants allegedly harmed by vaccines, using taglines like, ‘‘Healthy 14 week old infant gets 8 vaccines and dies within 24 h.” Other advertisements shared videos of parents describing their vaccine-injured children and/or how to live a life without vaccines. One advertisement promoted a candidate running on a vaccine choice platform in California. Several others included links to products and events.
Lena Sun reports on the study at The Washington Post:
 Researchers said the results surprised them. Much of the anti-vaccine content posted on social media platforms such as Facebook and Twitter may appear to be organic, grass-roots discussions led by neighborhood groups and concerned parents, said David A. Broniatowski, an associate professor at George Washington University and one of the authors of the study.
“In fact,” said Broniatowski, who studies group decision-making, “what we are seeing is a small number of motivated interests that are trying to disseminate a lot of harmful content.” The small group of anti-vaccine ad buyers successfully used the ads to reach targeted audiences.