Unexplained sudden death, including sudden infant death syndrome (SIDS), in the first and second years of life: Case definition and guidelines for collection, analysis, and presentation of immunization safety data

The suddenness of the death itself remains somewhat speculative, because it generally occurs at an unknown interval after the child was last seen alive and apparently well. Since infant primary immunization schedules temporally coincide with the peak age for the incidence of sudden infant death syndrome (SIDS), speculation about the association of immunization and SIDS may arise when deaths follow vaccinations, despite their predictable occurrence by chance alone [1,2]. [...]we would like to thank the members of the WHO/CIOMS Working Group on Vaccine Pharmacovigilance (http://www.cioms.ch/frame_current_programme.htm) for the review of, constructive comments on, and endorsement of this document.