Research Strategies for Assessing Adverse Events Associated withVaccines: A Workshop Summary
INTRODUCTION AND BACKGROUND
Between 1989 and 1994 the Institute of Medicine (IOM) carried outcomprehensive reviews of the scientific evidence concerning the possibleadverse effects of childhood vaccines. The studies, sponsored bythe U.S. Public Health Service (PHS), were called for by the NationalChildhood Vaccine Injury Act of 1986 (Public Law 99-660) and resultedin the volumes Adverse Effects of Pertussis and Rubella Vaccines (Institute of Medicine, 1991), Adverse Events Associated with Childhood Vaccines: Evidence Bearing on Causalitythe scientific evidence concerning the adverse effects of nine vaccines(for a total of more than 75 specific relations between vaccinesand adverse events). Committee members were struck by the lack ofevidence relating to causality for these adverse events. For abouttwo-thirds of the relations evaluated, the committees found eitherthat there was no evidence bearing on the question of causality orthat the available evidence was insufficient or inadequate to makea determination about causality.
Cognizant of this problem, in late 1993 the PHS asked IOM to holda scientific workshop to discuss the research strategies that couldmost fruitfully add to the assessment of the causal relation betweenvaccines and adverse events. The Committee to Study New Researchon Vaccines, which had been charged primarily with the study thatresulted in the 1994 DPT report, hosted such a