title: Antibody responses and persistence in the two years after immunization with two acellular vaccines and one whole-cell vaccine against pertussis.
abstract: OBJECTIVE
  To evaluate the persistence of specific antibodies induced by primary immunization with three doses of two three-component acellular vaccines against pertussis with an observed efficacy of 84%, and one whole-cell vaccine with an observed efficacy of 36%.
  
  
  METHODS
  Serum samples were collected from a subsample of 1572 children from the Italian double-blind, placebo-controlled, randomized trial of vaccines used in 15,601 children at three time points: before administration of the first dose of vaccine, and 1 month and approximately 15 months after administration of the third dose. Further evaluation included pooled cross-sectional analysis of serum specimens associated with episodes of cough (which were not laboratory confirmed as pertussis infection) occurring among the entire population enrolled in the trial.
  
  
  RESULTS
  With both acellular vaccines there was a fast and steep decrease in geometric mean antibody titers to pertussis toxin, filamentous hemagglutinin, and pertactin after vaccination. Mean titers were close to the limit of detection 15 months after primary immunization. The immunogenicity of the whole-cell study vaccine was poor 1 month after the third dose, and no antibody was detected in nearly all children 15 months after whole-cell vaccination.
  
  
  CONCLUSIONS
  Although the study acellular pertussis vaccines induced a strong primary specific antibody response in almost all recipients, the duration of the response was limited. Sustained high-level production of antibody to the antigens tested does not account for the observed efficacy of acellular pertussis vaccines.
authors.affiliation: Laboratory of Bacteriology, Istituto Superiore di Sanità, Rome, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Giuliano
authors.forename: P
authors.initials: P
authors.lastname: Mastrantonio
authors.forename: A
authors.initials: A
authors.lastname: Giammanco
authors.forename: A
authors.initials: A
authors.lastname: Piscitelli
authors.forename: S
authors.initials: S
authors.lastname: Salmaso
authors.forename: S G
authors.initials: SG
authors.lastname: Wassilak
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood*; D000917:Antibody Formation; D001886:Bordetella pertussis / Q000276:immunology*; D016466:CHO Cells; D006224:Cricetinae; D015721:Diphtheria-Tetanus-Pertussis Vaccine / Q000276:immunology; D004311:Double-Blind Method; D004797:Enzyme-Linked Immunosorbent Assay; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D037342:Pertussis Toxin; D010567:Pertussis Vaccine / Q000276:immunology; D013997:Time Factors; D014611:Vaccination; D010566:Virulence Factors, Bordetella / Q000276:immunology; D014917:Whooping Cough / Q000276:immunology / Q000517:prevention & control*
chemical_list: D000907:Antibodies, Bacterial; D015721:Diphtheria-Tetanus-Pertussis Vaccine; D010567:Pertussis Vaccine; D010566:Virulence Factors, Bordetella; D037342:Pertussis Toxin