title: Immunization Monitoring Program, Active: a model of active surveillance of vaccine safety.
abstract: In Canada since 1993 the nation's passive system for reporting postimmunization adverse events has been supplemented by the active surveillance of inpatients at 10 to 12 pediatric referral centers, a system referred to as the Immunization Monitoring Program, Active. Participating centers are located from coast-to-coast and receive referrals from every province and territory. Approximately 20 percent of the population aged 0 to 12 years lives in the immediate vicinity of these centers. Nurse monitors at each center search for numerous target conditions, including postimmunization adverse events and vaccine-preventable infections. Vaccine safety observations have included (1) a substantial decrease in the risk of the development of febrile seizures and hypotonic-hyporesponsive episodes since the country switched from whole-cell to acellular pertussis-containing vaccines, (2) no evidence for encephalopathy resulting from the latter vaccines, (3) a generally benign outcome with postimmunization thrombocytopenia cases, and (4) an unexpectedly high rate of disseminated bacille Calmette-Guérin infections among aboriginal infants. Concomitant disease surveillance has been important for sustaining the surveillance system because few postimmunization adverse events require hospital admission.
authors.affiliation: Immunization Monitoring Program, Active (IMPACT), Ottawa, Ontario, Canada. dscheifele@cw.bc.ca
authors.forename: David W
authors.initials: DW
authors.lastname: Scheifele
authors.forename: Scott A
authors.initials: SA
authors.lastname: Halperin
mesh_terms: D016907:Adverse Drug Reaction Reporting Systems; D002170:Canada / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D003140:Communicable Disease Control; D003141:Communicable Diseases / Q000453:epidemiology; D004673:Encephalomyelitis, Acute Disseminated / Q000453:epidemiology / Q000209:etiology; D006801:Humans; D007114:Immunization / Q000009:adverse effects*; D017589:Immunization Programs; D007223:Infant; D009123:Muscle Hypotonia / Q000453:epidemiology / Q000209:etiology; D010243:Paralysis / Q000453:epidemiology / Q000209:etiology; D011159:Population Surveillance; D003294:Seizures, Febrile / Q000453:epidemiology / Q000209:etiology; D013921:Thrombocytopenia / Q000453:epidemiology / Q000209:etiology; D014376:Tuberculosis / Q000453:epidemiology / Q000209:etiology; D014612:Vaccines / Q000009:adverse effects*
chemical_list: D014612:Vaccines