title: Prevalence of pertussis antibodies in maternal delivery, cord, and infant serum.
abstract: BACKGROUND
  Passively acquired maternal antibodies protect infants from many pathogens. With increasing reports of infant pertussis, we evaluated pertussis antibodies in maternal-infant paired sera from 1999-2000.
  
  
  METHODS
  Antibodies to pertussis toxin (PT), filamentous hemagglutinin (FHA), and fimbrial proteins (FIM) were measured by validated IgG-specific enzyme-linked immunosorbant assay (ELISA) in 64 maternal-umbilical cord serum pairs and in 61 of 64 infant sera. Geometric mean concentrations (GMCs) of pertussis antibodies and cord : maternal GMC ratios were calculated.
  
  
  RESULTS
  Mean maternal age and gestation were 29.7 years (range, 19-42) and 39.3 weeks (range, 35.6-40.9), and 81% of mothers were white. GMCs of maternal antibodies at delivery (ELISA units/mL) were 2.4 for PT, 6.9 for FHA, and 13 for FIM. Cord GMCs were 169%, 178%, and 157% of maternal delivery values for PT, FHA, and FIM, respectively, demonstrating active placental transfer (P<.001). Pertussis-specific IgG values for each antigen decayed to below the threshold of detection by age 2 months.
  
  
  CONCLUSIONS
  Despite efficient placental transfer, low maternal pertussis antibody levels and their rapid decay in infant sera leave infants with little humoral protection against pertussis. These data support the rationale for maternal or neonatal immunization, with acellular pertussis vaccines, to prevent life-threatening pertussis in early infancy.
authors.affiliation: Section of Infectious Diseases, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA. chealy@bcm.tmc.edu
authors.forename: C Mary
authors.initials: CM
authors.lastname: Healy
authors.forename: Flor M
authors.initials: FM
authors.lastname: Munoz
authors.forename: Marcia A
authors.initials: MA
authors.lastname: Rench
authors.forename: Natasha B
authors.initials: NB
authors.lastname: Halasa
authors.forename: Kathryn M
authors.initials: KM
authors.lastname: Edwards
authors.forename: Carol J
authors.initials: CJ
authors.lastname: Baker
mesh_terms: D018829:Adhesins, Bacterial / Q000276:immunology*; D000328:Adult; D000907:Antibodies, Bacterial / Q000097:blood*; D001886:Bordetella pertussis / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005312:Fetal Blood / Q000276:immunology; D036781:Fimbriae Proteins / Q000276:immunology*; D006388:Hemagglutinins / Q000276:immunology*; D006801:Humans; D007112:Immunity, Maternally-Acquired; D007074:Immunoglobulin G / Q000097:blood; D007223:Infant; D007231:Infant, Newborn; D007700:Kinetics; D008297:Male; D037342:Pertussis Toxin / Q000276:immunology*; D011247:Pregnancy; D010566:Virulence Factors, Bordetella / Q000276:immunology*; D014917:Whooping Cough / Q000276:immunology
chemical_list: D018829:Adhesins, Bacterial; D000907:Antibodies, Bacterial; D006388:Hemagglutinins; D007074:Immunoglobulin G; D010566:Virulence Factors, Bordetella; C065273:filamentous hemagglutinin adhesin, Bordetella pertussis; D036781:Fimbriae Proteins; D037342:Pertussis Toxin