Background: The rhesus rotavirus tetravalent vaccine (RotaShield) had an efficacy of 75%-100% in preventing severe rotavirus disease in prelicensure clinical trials. Before RotaShield's withdrawal because of reports of intussusception, there was an opportunity to evaluate the postlicensure effectiveness of the vaccine. The objective of this study was to determine the effectiveness of the RotaShield vaccine against rotavirus gastroenteritis requiring hospitalization and to evaluate factors associated with vaccine receipt.
Methods: Rotavirus cases were identified through active hospital-based rotavirus surveillance at 3 children's hospitals in Cincinnati, New Orleans and Providence. Cases were selected if they had been eligible for vaccine during the 10-month period when vaccine was available. Controls were matched to cases by date and county or state of birth. Immunization records were obtained from cases and controls to document receipt of RotaShield. Vaccine effectiveness (VE) was calculated for 1, 2, and 3 doses of vaccine with 95% confidence intervals (CI).
Results: For the 10-month period, 136 cases and 440 controls were enrolled. For 3 versus 0 doses of RotaShield, the VE was 100% (CI: 75%, 100%); for 2 versus 0 doses, the VE was 100% (CI: 62%, 100%), and for 1 versus 0 doses the VE was 89% (CI: 49%, 97%). RotaShield receipt was associated with white race, having more than 1 adult in the household, having insurance and having an older, more educated mother.
Conclusions: This postlicensure study of RotaShield effectiveness found the vaccine to be highly effective in preventing rotavirus disease requiring hospitalization.