Intussusception among recipients of rotavirus vaccine: Reports to the vaccine adverse event reporting system

Background. Rotavirus vaccine was licensed on August 31, 1998, and subseque ntly recommended for routine use among infants. To assess rare adverse even ts, postlicensure surveillance was conducted. Objective. To describe the cases of intussusception among rotavirus vaccine recipients reported to the Vaccine Adverse Event Reporting System from Oct ober 1998 through December 1999. Setting and Participants. Infants vaccinated with rotavirus vaccine in the United States. Outcome Measures. Intussusception confirmed by radiology, surgery, or autop sy report with medical record documentation or confirmed by a primary healt h care provider. Results. There were 98 confirmed cases of intussusception after vaccination with rotavirus vaccine reported to the Vaccine Adverse Event Reporting Sys tem; 60 of these developed intussusception within 1 week after vaccination. Based on calculations using vaccine distribution data and intussusception incidence rates from 2 separate databases, an estimated 7 to 16 cases would have been expected to occur in the week after vaccination by chance alone. Conclusion. Using a passive surveillance system for vaccine adverse events, we observed at least a fourfold increase over the expected number of intus susception cases occurring within 1 week of receipt of rotavirus vaccine. O ther studies were initiated to further define the relationship between rota virus vaccine and intussusception. In light of these and other data, the ro tavirus vaccine manufacturer voluntarily removed its product from the marke t, and the recommendation for routine use of rotavirus vaccine among US inf ants has been withdrawn.