Pertussis antibodies in postpartum women and their newborns

J Perinatol. 2010 Feb;30(2):93-7. doi: 10.1038/jp.2009.138. Epub 2009 Oct 8.


Objective: To (1) determine the proportion of mothers and infants who had levels of IgG antibody to pertussis antigens predicted to be potentially protective at delivery; (2) evaluate the efficiency of maternal-infant antibody transport; (3) extrapolate infant antibody titers at 6 weeks; and (4) identify maternal factors associated with potentially protective infant antibodies.

Study design: Sera from mother-infant pairs from February 2006 through to April 2007 were tested for antibody to pertussis antigens by standardized ELISA (enzyme-linked immunosorbent assay). Potentially protective antibody levels were defined as >5 ELISA units (EU) for pertussis toxin (PT), and >10 EU for fimbriae (FIM) and pertactin (PRN). Serological evidence of previous maternal infection was defined from antibody to four antigens by k-means cluster analysis.

Result: In total, 21% (17/81) of mothers and 26% (21/81) of infants had potentially protective antibody levels at delivery. Mean infant-maternal antibody ratios for PT, FIM and PRN were 1.26, 1.36 and 1.31, respectively. At 6 weeks, 11% (9/81) of infants were predicted to have potentially protective antibody levels. Using cluster analysis, 9% (7/81) of mothers had evidence of previous pertussis infection. Infants born to these mothers were predicted to be more likely to have potentially protective antibodies at 6 weeks (43%) than those born to mothers without previous infection (8%) (P=0.03).

Conclusion: Approximately 75% of infants were born with pertussis antibody levels lower than the modest levels associated with potential protection. Despite effective antibody transfer, nearly 90% of infants were predicted to have little antibody by 6 weeks. Maternal immunization before or during pregnancy might simulate previous pertussis infection and help protect infants through the first months of life.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adolescent
  • Adult
  • Antibodies, Bacterial / blood*
  • Bacterial Outer Membrane Proteins / immunology
  • Bordetella pertussis / immunology*
  • Female
  • Fimbriae, Bacterial / immunology
  • Humans
  • Immunity, Maternally-Acquired*
  • Infant, Newborn
  • Pertussis Toxin / immunology
  • Pregnancy
  • Virulence Factors, Bordetella / immunology
  • Young Adult


  • Antibodies, Bacterial
  • Bacterial Outer Membrane Proteins
  • Virulence Factors, Bordetella
  • pertactin
  • Pertussis Toxin