title: Acellular pertussis vaccines. Efficacy and evaluation of clinical case definitions.
abstract: The efficacy of two acellular pertussis vaccines was estimated for various clinical case definitions, with and without the requirement of culture confirmation, from a randomized trial in Sweden. Efficacy increased with duration of coughing spasms and when the case definition included whoops or whoops plus at least nine coughing spasms a day. After deletion of clinical cases not believed to be caused by pertussis, efficacies were closer to the higher values for culture-confirmed disease. Nonspecificity of the clinical criterion "21 days of coughing spasms with whoops" resulted in estimates of predictive value for pertussis of 85% for placebo recipients and 56% for vaccinees. We conclude that laboratory confirmation of suspected cases is needed in pertussis vaccine trials. A suggested case definition is 21 days or more of coughing spasms with confirmation by culture, serologic study, or household exposure to culture-confirmed pertussis.
authors.affiliation: National Institute of Allergy and Infectious Diseases, Bethesda, Md.
authors.forename: W C
authors.initials: WC
authors.lastname: Blackwelder
authors.forename: J
authors.initials: J
authors.lastname: Storsaeter
authors.forename: P
authors.initials: P
authors.lastname: Olin
authors.forename: H O
authors.initials: HO
authors.lastname: Hallander
mesh_terms: D006801:Humans; D007167:Immunotherapy / Q000592:standards*; D007223:Infant; D010567:Pertussis Vaccine / Q000627:therapeutic use*; D012107:Research Design / Q000592:standards; D012307:Risk Factors; D012680:Sensitivity and Specificity; D013548:Sweden / Q000453:epidemiology; D014917:Whooping Cough / Q000175:diagnosis* / Q000453:epidemiology / Q000517:prevention & control
chemical_list: D010567:Pertussis Vaccine