title: Effects of pertussis vaccination on disease: vaccine efficacy in reducing clinical severity.
abstract: We estimated the effectiveness of pertussis vaccination in reducing the clinical severity of breakthrough disease among vaccinated individuals from a comprehensive follow-up study of a community of 30,000 residents of Niakhar, Senegal, in 1993. A physician examined all children with potential pertussis (cough of >7 days' duration). Samples were collected from 97% of these children for culture or serologic testing as part of the active surveillance for a pertussis vaccine trial. Cases of pertussis were defined by confirmation through culture or serologic testing or by a history of contact with a person with culture-confirmed pertussis. Among children with confirmed cases, severity of illness was assessed according to a scale that combined clinical signs and symptoms. The efficacy of the vaccine in reducing disease severity was 48% (95% confidence interval, 39%-55%) among children vaccinated with 3 doses of whole-cell (67%) or acellular (32%) vaccine. Primary cases were more severe than secondary cases in residential compounds. Pertussis vaccination is effective in reducing the severity of illness.
authors.affiliation: Niakhar Project, Institut de Recherche pour le Développement, Dakar, Senegal. mprezio@sph.emory.edu
authors.forename: Marie-Pierre
authors.initials: MP
authors.lastname: Préziosi
authors.forename: M Elizabeth
authors.initials: ME
authors.lastname: Halloran
mesh_terms: D001886:Bordetella pertussis; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D010567:Pertussis Vaccine / Q000008:administration & dosage*; D012675:Senegal; D014917:Whooping Cough / Q000503:physiopathology* / Q000517:prevention & control*
chemical_list: D010567:Pertussis Vaccine