Context Individuals searching the Internet for vaccine information may find
antivaccination Web sites. Few published studies have systematically evaluated
Objectives To examine antivaccination Web site attributes and to delineate the
specific claims and concerns expressed by antivaccination groups.
Design and Setting In late 2000, using a metasearch program that incorporates 10 other
search engines, we reviewed and analyzed 772 links to find 12 Web sites that
promulgated antivaccination information. Analyzing links from these 12 sites
yielded another 10 sites, producing a total of 22 sites for study. Using a
standardized form, 2 authors (R.M.W., L.K.S.) systematically evaluated these
sites based on specific content and design attributes.
Main Outcome Measures Presence or absence of 11 Web site content attributes (antivaccination
claims) and 10 Web site design attributes.
Results The most commonly found content claims were that vaccines cause idiopathic
illness (100% of sites), vaccines erode immunity (95%), adverse vaccine reactions
are underreported (95%), and vaccination policy is motivated by profit (91%).
The most common design attributes were the presence of links to other antivaccination
sites (100%of sites), information for legally avoiding immunizations (64%),
and the use of emotionally charged stories of children who had allegedly been
killed or harmed by vaccines (55%).
Conclusion Antivaccination Web sites express a range of concerns related to vaccine
safety and varying levels of distrust in medicine. The sites rely heavily
on emotional appeal to convey their message.