Anti-Vaccination Websites Use Misleading Scientific Data to Support Claims

A study finds that anti-vaccine websites frequently use misleading scientific facts to justify their claims against vaccination.

More than two-thirds of anti-vaccination websites use some form of represented scientific evidence to support their claims that vaccines are harmful, according to research presented at the American Public Health Association’s Annual Meeting.

Megan Moran, PhD, associate professor at the Bloomberg School’s Department of Health, Behavior and Society, and lead author of the study, presented the data.

The researchers searched Google, Bing, and Yahoo to find websites, blogs, Facebook pages, and health websites with content concerning childhood vaccinations.

Four coders searched the websites for vaccine misinformation, the source of the misinformation, and determined the persuasive tactic used on the website. The researchers also noted any behaviors and values promoted on the website that could help vaccine promotion campaigns develop better material to better inform parents about vaccines.

In a content analysis of 480 anti-vaccination websites, Dr Moran and her colleagues noted that most used misinformation or pseudoscience; 65.5% had data claiming that vaccines were dangerous, 62.2% contained misinformation that vaccines caused autism, and 41.1% said that vaccines can cause brain injuries. Overall, 64.7% of the websites used scientific evidence and 30% used anecdotes to support their claim.

“The biggest global takeaway is that we need to communicate to the vaccine hesitant parent in a way that resonates with them and is sensitive to their concerns,” Dr Moran said in a press release.

According to the analysis, 18.5% of the websites promoted eating healthy, 5.2% promoted eating organic foods, and 5.5% promoted breastfeeding.

“In our review, we saw communication for things we consider healthy, such as breastfeeding, eating organic, the types of behavior public health officials want to encourage,” Dr Moran said in the release. “I think we can leverage these good things and reframe our communication in a way that makes sense to those parents resisting vaccines for their children.”

The results suggest that clinicians can use relevant scientific data and parents’ anecdotes to encourage vaccination.


  1. Moran M. Abstract 329083. Why Are Anti-Vaccine Messages So Persuasive? A Content Analysis of Anti-Vaccine Websites to Inform the Development of Vaccine Promotion Strategies. Presented at the American Public Health Association; November 3, 2015; Chicago, IL.