evidence: The authors evaluated recent immunization with DTP as a possible risk factor for SIDS during a 10-year period in Tennessee. They found no increase in the risk of SIDS after immunization with DTP vaccine and no correlation between SIDS and age at first immunization. Additionally, the rate of SIDS decreased in the first week after immunization. Hoffman HJ, Hunter JC, Damus K, Pakter J, Peterson DR, et al. Diphtheria-tetanus-pertussis immunization and sudden infant death: results of the National Institute of Child Health and Human Development Cooperative Epidemiological Study of Sudden Infant Death Syndrome Risk Factors. Pediatrics 1987;79:598-611. The authors investigated the possible association between diphtheria-tetanus-pertussis (DTP) immunization and subsequent occurrence of sudden infant death in the United States using data from a national SIDS epidemiological database. They found no temporal association between SIDS and DTP vaccine receipt. Infants with SIDS were less likely to have been immunized than infants without SIDS.