ABSTRACT. Background. Rotavirus vaccine was licensed on August 31, 1998, and subsequently recommended for routine use among infants. To assess rare adverse events, postlicensure surveillance was conducted.Objective. To describe the cases of intussusception among rotavirus vaccine recipients reported to the Vaccine Adverse Event Reporting System from October 1998 through December 1999.
Setting and Participants. Infants vaccinated with rotavirus vaccine in the United States.Outcome Measures. Intussusception confirmed by radiology, surgery, or autopsy report with medical record documentation or confirmed by a primary health care provider.Results. There were 98 confirmed cases of intussusception after vaccination with rotavirus vaccine reported to the Vaccine Adverse Event Reporting System; 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 intussusception cases occurring within 1 week of receipt of rotavirus vaccine. Other studies were initiated to further define the relationship between rotavirus vaccine and intussusception. In light of these and other data, the rotavirus vaccine manufacturer voluntarily removed its product from the market, and the recommendation for routine use of rotavirus vaccine among US infants has been withdrawn. T he live, oral, rhesus-human rotavirus reassortant-tetravalent vaccine (RRV-TV) was licensed for use in the United States on August 31, 1998. It was subsequently recommended for routine use in infants in a 3-dose series given at 2, 4, and 6 months of age. 1,2 This recommendation was based on the morbidity and economic burden of severe dehydrating rotavirus gastroenteritis among infants and young children. 1 In prelicensure clinical trials, 5 cases of intussusception were noted among 10 054 vaccinees who had received 1 of 3 different formulations of rotavirus vaccine. Two of these 5 cases received RRV-TV. All 5 intussusception cases occurred after either dose 2 or 3. The cases occurred 6 to 51 days after rotavirus vaccination; 3 of these cases occurred on days 6 or 7. In contrast, 1 case of intussusception was noted among 4633 controls. 3 The difference in the proportion of children who developed intussusception in the vaccinated and unvaccinated groups was not statistically significant. Although there was insufficient evidence to conclude that the association between RRV-TV and intussusception was causal rather than temporal, intussusception was noted in the package insert, and postlicensure surveillance for intussusception was recommended by the Advisory Committee on Immunization Practices (ACIP). 1 Distribution of RRV-TV commenced in October 1998. After vaccine introduction, reports to the Vaccine ...