title: Long-term immunogenicity of a single dose of acellular pertussis vaccine in paediatric health-care workers.
abstract: OBJECTIVE
  Monitor the long-term immunogenicity of a single dose of acellular pertussis vaccine in health-care workers.
  
  
  METHODS
  German health-care workers and child-care workers received a single dose of a monovalent acellular pertussis vaccine (PAC-Mérieux) in an open-label study. Blood samples were taken before (n=261), 4 weeks after (n=246), 1 year (n=187), 2 years (n=53), 3 years (n=134) and 4 years (n=37) after vaccination. IgG- and IgA-anti-pertussis-toxin (PT), IgG- and IgA-anti-filamentous hemagglutinin (FHA), and IgG-anti-pertactin (PRN) were measured by ELISA.
  
  
  RESULTS
  Of all subjects, 97.1%, 99.2% and 97.2% had an antibody response to PT, FHA and PRN, respectively. Four weeks after vaccination the median titres of IgG antibodies to PT, FHA and PRN were 314, 785 and 84 EU/l, respectively, and all vaccinees had an immune response to at least one pertussis antigen. IgA-anti-PT and IgA-anti-FHA responses were found in 63.4% and 96.3% of subjects with a median titre of 30 and 196 EU/ml, respectively. The titre of IgG-anti-PT decreased slowly with a median concentration of 76, 71, 71 and 63 EU/ml after 1, 2, 3 and 4 years, respectively. Secondary titre increases were observed in 0.5%, 3.3%, 5.6% and 12.5% of the vaccinees 1, 2, 3, and 4 years after vaccination.
  
  
  CONCLUSIONS
  In German health paediatric care workers long-lasting immune responses with high antibody levels could be induced by a single dose of acellular pertussis vaccine. A renewed contact with B. pertussis antigens resulted in a measurable immune response to PT between 0.5% (1 year p.v.) and 12.5% (4 years p.v.).
authors.affiliation: Landesamt für Gesundheit und Soziales Mecklenburg-Vorpommern, Rostock, Germany.
authors.forename: Martina
authors.initials: M
authors.lastname: Littmann
authors.forename: Christel
authors.initials: C
authors.lastname: Hülsse
authors.forename: Marion
authors.initials: M
authors.lastname: Riffelmann
authors.forename: Carl Heinz
authors.initials: CH
authors.lastname: Wirsing von König
mesh_terms: D018829:Adhesins, Bacterial / Q000276:immunology; D000293:Adolescent; D000328:Adult; D000907:Antibodies, Bacterial / Q000097:blood; D000992:Antitoxins / Q000097:blood; D001425:Bacterial Outer Membrane Proteins / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D005858:Germany; D006282:Health Personnel; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D008137:Longitudinal Studies; D008875:Middle Aged; D037342:Pertussis Toxin / Q000276:immunology; D010567:Pertussis Vaccine / Q000008:administration & dosage / Q000276:immunology*; D022282:Vaccines, Acellular / Q000008:administration & dosage / Q000276:immunology; D010566:Virulence Factors, Bordetella / Q000276:immunology
chemical_list: D018829:Adhesins, Bacterial; D000907:Antibodies, Bacterial; D000992:Antitoxins; D001425:Bacterial Outer Membrane Proteins; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D010567:Pertussis Vaccine; D022282:Vaccines, Acellular; D010566:Virulence Factors, Bordetella; C065273:filamentous hemagglutinin adhesin, Bordetella pertussis; C068929:pertactin; D037342:Pertussis Toxin