Gastrointestinal reactions and rotavirus vaccination based upon analysis of the Vaccine Adverse Events Reporting System (VAERS) database for 1999. A model for the calculation of the incidence rates and statistical significance of adverse events following immunization

Background/Aims: The purpose of this study was to extend previous publications and examine the Vaccine Adverse Events Reporting System (VAERS) database for the incidence of gastrointestinal reactions reported following tetra-valent rhesus-human reassortant rotavirus vaccine (RRV-TV). Methodology: The VAERS database was analyzed for adverse reactions reported for the entire year of 1999 following RRV-TV using Microsoft Access. In this study, the incidence rates of adverse reactions reported to VAERS following acellular diphtheria, pertussis and tetanus (DTaP) vaccine, whole-cell DTP vaccine, live polio (OPV) vaccine and pediatric hepatitis B vaccine were used as control vaccine groups. Results: The results of a chi-square analysis showed that rotavirus vaccine was statistically significantly over represented by serious gastrointestinal reactions in comparison to vaccine control groups. Conclusions: This analysis demonstrated that the VAERS database provides a way to detect whether RRV-TV elevates the risk of adverse reactions compared to control vaccines given to similar age groups when appropriate denominators (number of annual doses given) are employed. Because of its massive size and the availability of numerous vaccine control groups, the VAERS database provides data on adverse reactions following vaccination that is available nowhere else.