In immunization safety research, individuals are considered at risk for the development of certain adverse events following immunization (AEFI) within a specific period of time referred to as the risk interval. These intervals should ideally be determined based on biologic plausibility considering features of the AEFI, presumed or known pathologic mechanism, and the vaccine. Misspecification of the length and timing of these intervals may result in introducing bias in epidemiologic and clinical studies of immunization safety. To date, little work has been done to formally assess and determine biologically plausible and evidence-based risk intervals in immunization safety research. In this report, we present a systematic process to define biologically plausible and evidence-based risk interval estimates for two specific AEFIs, febrile seizures and acute disseminated encephalomyelitis. In addition, we review methodologic issues related to the determination of risk intervals for consideration in future studies of immunization safety.
Biologically plausible and evidence-based risk intervals in immunization safety research
Authors: Rowhani-Rahbar A; Klein NP; Dekker CL; Edwards KM; Marchant CD; Vellozzi C; Fireman B; Sejvar JJ; Halsey NA; Baxter R; Risk Interval Working Group of the Clinical Immunization Safety Assessment Network
Vaccine. 2012 Dec 17;31(1):271-7. Epub 2012 Jul 24.