title: Immunogenicity of a five-component acellular pertussis vaccine in infants and young children.
abstract: OBJECTIVE
  To compare the reactogenicity and immunogenicity of an acellular vaccine containing pertussis toxoid, filamentous hemagglutinin, and fimbriae 2 and 3, with and without the 69-kd membrane protein, alone or combined with diphtheria and tetanus toxoids.
  
  
  METHODS
  One hundred thirty-seven 17- to 18-month-old and 22 4- to 6-year-old children who had received three or four previous doses of whole-cell vaccine, respectively, were recruited from public health immunization clinics.
  
  
  METHODS
  Three groups of children were sequentially enrolled in the study to receive the acellular pertussis vaccine with or without a 69-kd protein (CP4 or CP5, 17- to 18-month-old children), the two vaccines combined with diphtheria and tetanus toxoids (CP4DT or CP5DT, 17- to 18-month-old children), or the CP5DT vaccine (4- to 6-year-old children). Children were assigned to the first two groups in a randomized and double-blind fashion; the last group was formed by open enrollment. Data regarding adverse reactions were recorded by the parents and collected via a structured interview administered seven times, five times during the first 72 hours. Serum samples were obtained before and 1 month after the immunization, and antibodies against each constituent of the vaccine were measured.
  
  
  RESULTS
  A systemic adverse reaction was reported in 40% to 65.7% of 17- to 18-month-old and 38.1% of 4- to 6-year-old children; no severe reactions occurred. A local reaction was reported in 8.6% to 29.4% and 71.4% of children, respectively. No differences were detected between respectively. No differences were detected between vaccines; inclusion of the 69-kd membrane protein did not increase reactogenicity. All vaccines elicited an antibody response to all antigens contained in the formulation.
  
  
  CONCLUSIONS
  The five-component acellular pertussis vaccine (Connaught Laboratories Ltd, Willowdale, Ontario) is safe and immunogenic in 17- to 18-month-old and 4- to 6-year-old children. The 69-kd protein was immunogenic, and its inclusion neither increased side effects associated with the vaccine nor adversely affected the antibody response to the other components.
authors.affiliation: Department of Pediatrics, Dalhousie University, Halifax, Nova Scotia.
authors.forename: S A
authors.initials: SA
authors.lastname: Halperin
authors.forename: L
authors.initials: L
authors.lastname: Barreto
authors.forename: B
authors.initials: B
authors.lastname: Friesen
authors.forename: W
authors.initials: W
authors.lastname: Meekison
mesh_terms: D018829:Adhesins, Bacterial; D000907:Antibodies, Bacterial / Q000097:blood*; D000942:Antigens, Bacterial / Q000009:adverse effects* / Q000276:immunology*; D001886:Bordetella pertussis / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D015721:Diphtheria-Tetanus-Pertussis Vaccine / Q000009:adverse effects* / Q000276:immunology*; D004311:Double-Blind Method; D004341:Drug Evaluation; D016903:Drug Monitoring; D010861:Fimbriae, Bacterial / Q000276:immunology; D006388:Hemagglutinins / Q000009:adverse effects* / Q000276:immunology*; D006801:Humans; D007223:Infant; D010567:Pertussis Vaccine / Q000009:adverse effects* / Q000145:classification / Q000276:immunology*; D017778:Vaccines, Combined; D010566:Virulence Factors, Bordetella
chemical_list: D018829:Adhesins, Bacterial; D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D015721:Diphtheria-Tetanus-Pertussis Vaccine; D006388:Hemagglutinins; D010567:Pertussis Vaccine; D017778:Vaccines, Combined; D010566:Virulence Factors, Bordetella; C065273:filamentous hemagglutinin adhesin, Bordetella pertussis