Immunization Science

Characteristics of Anti-vaccination Web Sites

The article

Content and Design Attributes of Antivaccination Web Sites. Wolfe RM, Sharp LK, Lipsky MS. JAMA 2002;287:3245-3248.

Explanatory Note: As many as two thirds of adults in the United States use the internet and most of them (80%) look for health information. Most of these people believe that the information they find online is reliable, although a great deal of it is not. Unfortunately, there is a great deal of misinformation online.

The question

What are the content and design characteristics of anti-vaccination web sites?

The study

The researchers searched the internet for key words relating to vaccines, identifying 772 sites which they reviewed. They defined an anti-vaccine website as one that “contained content specifically opposing vaccination for human infants or children.”

Review of the web site included extracting specific types of content and characteristics of web site design.

The findings

The researchers identified 22 websites for this study, 12 from the original 772 sites and 12 additional ones that were linked to these sites.

All of the sites suggested that vaccines cause illnesses or disorders of unknown cause, such as autism, sudden infant death syndrome, immune dysfunction, diabetes, neurological disorders, allergic rhinitis, eczema, and asthma.

All of the sites linked to other anti-vaccine web sites.

Most of the sites provided personal accounts of children whose parents felt they had been harmed by vaccines. Most also provided information on how to avoid vaccinations. Seven sites (32%) displayed pictures of menacing needles, and 5 sites (23%) displayed pictures of children allegedly harmed or killed by vaccine reactions.

Many of the sites promoted homeopathy, alternative health, and natural methods of enhancing immunity instead of vaccinations.

Most sites suggested that vaccine public health policy is motivated by profit and that universal vaccination recommendations promote a cover-up of vaccine adverse effects.

The relevance/bottom line

Anti-vaccination web sites express a variety of claims that rely on emotion-filled anecdotes. Much of the content is largely unsupported by peer-reviewed scientific literature. Although all concerns about vaccine safety and effectiveness are important, these anti-vaccine web sites confuse timing with cause and effect. In other words, the anti-vaccine web sites suggest that because something bad happens to a child after being immunized, the vaccine must have caused the problem.

NNii’s comments

The internet has proven to be an extraordinary means to easily access information. Not all of that information is reliable, however, and may confuse parents facing vaccination decisions. It is important to make informed decisions about immunization based on good information (See Evaluating information on the web).