In August 1998, the US Food and Drug Administration licensed the first vaccine against rotavirus, the most important cause of severe childhood diarrhea. Fourteen months later, amid intense media activity, the vaccine was withdrawn after an association was found with intussusception. To examine the character of news media stories about rotavirus vaccine before and after intussusception became an issue, to evaluate what prompted the stories, and to assess the extent to which they evoked public reaction. We searched Lexis-Nexis and Video Monitoring Services of America databases for rotavirus vaccine stories from the first US clinical trials (January 1, 1987) until 17 months after withdrawal (March 31, 2001) and examined calls to the National Immunization Hotline during the period in which rotavirus vaccine information was captured (July 1-December 31, 1999). Mention of vaccine benefits and adverse events, classification of stories as positive, negative, or neutral toward the vaccine, story stimuli, and public response. We included 280 newspaper (primary subject of analysis), 49 wire service, and 257 television stories. Prior to identification of the intussusception association (January 1, 1987-July 14, 1999), 21% of 188 newspaper stories mentioned vaccine adverse events and only 2 stories were negative toward the vaccine. Ninety-nine percent of stories mentioned vaccine benefits. During the period surrounding withdrawal (July 15-December 31, 1999), 93% of 90 stories mentioned adverse events and 77% were negative toward the vaccine. Eighty-four percent mentioned vaccine benefits. The rate of stories per month was 14-fold greater than the preceding period (P<.001); temporal and geographic patterns of media and hotline activity were similar. Thereafter (January 1, 2000-March 31, 2001), only 2 stories focused on rotavirus vaccine. Scientific research or public health actions prompted 80% of stories. Wire service and television stories showed similar patterns. The increase in rotavirus stories in July 1999 was followed by an increase in calls to the National Immunization Hotline regarding rotavirus but not other topics. The number of rotavirus calls that month was 57% higher than for any other childhood vaccine for any month since the hotline began in 1997. Rotavirus calls ceased almost completely after withdrawal of the vaccine in October 1999. In response to reports about an adverse event, news media stories about vaccines can change abruptly from positivity to negativity. Since most vaccine stories may be stimulated by research and public health actions, opportunities exist to provide the media with accurate information necessary to avoid the "early idealization-sudden condemnation" pattern seen with rotavirus vaccine.