title: Respiratory syncytial virus transplacental antibody transfer and kinetics in mother-infant pairs in Bangladesh.
abstract: BACKGROUND
  Pneumonia is the leading cause of childhood mortality globally. Respiratory syncytial virus (RSV) is the most important viral cause of pneumonia. Maternal serum antibody protects infants from RSV disease. The objective of our study was to characterize RSV antibody levels in mother-infant pairs.
  
  
  METHODS
  Serial serum samples were collected from mother-infant pairs in Bangladesh from the third trimester of pregnancy to 72 weeks postpartum and tested using an RSV antibody microneutralization assay. Serologic infection was defined as a 4-fold increase in antibody titer. Maternal antibody half-life was calculated using infant antibody titers from birth to 20 weeks.
  
  
  RESULTS
  The ratio of infant cord blood to maternal serum RSV antibody titers in 149 mother-infant pairs was 1.01 (95% confidence interval [CI], .99-1.03). Maternal RSV antibody titers in the third trimester and at birth were strongly correlated (R = 0.68). Antibody half-life was 38 days (95% CI, 36-42 days). Higher cord blood RSV antibody titers were associated with a lower risk of serologic infection (P = .01) and maintenance of antibody titer above a potentially protective threshold (P < .001).
  
  
  CONCLUSIONS
  Efficient transplacental transfer of RSV-specific antibody from mother to the fetus was documented in mother-infant pairs in Asia. Higher cord blood antibody titers were associated with protection from serologic infection.
authors.affiliation: Department of Medicine.
authors.forename: Helen Y
authors.initials: HY
authors.lastname: Chu
authors.affiliation: Department of Global Health, Cincinnati Children's Hospital, Ohio.
authors.forename: Mark C
authors.initials: MC
authors.lastname: Steinhoff
authors.affiliation: Department of Laboratory Medicine, University of Washington.
authors.forename: Amalia
authors.initials: A
authors.lastname: Magaret
authors.affiliation: International Center for Diarrheal Disease Research, Dhaka, Bangladesh.
authors.forename: Khalequ
authors.initials: K
authors.lastname: Zaman
authors.affiliation: International Center for Diarrheal Disease Research, Dhaka, Bangladesh.
authors.forename: Eliza
authors.initials: E
authors.lastname: Roy
authors.affiliation: Department of Global Health, Cincinnati Children's Hospital, Ohio.
authors.forename: Gretchen
authors.initials: G
authors.lastname: Langdon
authors.affiliation: Department of Medicine, University of Rochester-Rochester General Hospital, New York.
authors.forename: Mary Anne
authors.initials: MA
authors.lastname: Formica
authors.affiliation: Department of Medicine, University of Rochester-Rochester General Hospital, New York.
authors.forename: Edward E
authors.initials: EE
authors.lastname: Walsh
authors.affiliation: Department of Pediatrics, Seattle Children's Hospital, Seattle, Washington.
authors.forename: Janet A
authors.initials: JA
authors.lastname: Englund
mesh_terms: D000293:Adolescent; D000914:Antibodies, Viral / Q000097:blood*; D001459:Bangladesh; D005260:Female; D006801:Humans; D007112:Immunity, Maternally-Acquired; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008431:Maternal-Fetal Exchange; D058725:Peripartum Period; D011247:Pregnancy; D018113:Respiratory Syncytial Virus, Human / Q000276:immunology*; D055815:Young Adult
chemical_list: D000914:Antibodies, Viral
keywords: antibody; maternal vaccine; respiratory syncytial virus