title: The Effect of Maternal Pertussis Immunization on Infant Vaccine Responses to a Booster Pertussis-Containing Vaccine in Vietnam.
abstract: BACKGROUND
  Maternal vaccination with an acellular pertussis (aP)-containing vaccine is a recommended strategy in a growing number of industrialized countries, to protect young infants from disease. Little is known on the effect of this strategy in low- and middle-income countries. Following a previous report on the effect of adding a pertussis and diphtheria component to the tetanus vaccination program in pregnant women in Vietnam, we report on infant immune responses to a booster aP vaccine dose in this randomized controlled clinical trial.
  
  
  METHODS
  Thirty infants of Tdap (tetanus, diphtheria, and acellular pertussis)-vaccinated pregnant women and 37 infants of women vaccinated with a tetanus-only vaccine received a fourth aP-containing vaccine dose in the second year of life. Blood was taken 1 month after the fourth infant dose. Immunoglobulin G (IgG) antibodies against pertussis toxin (PT), filamentous hemagglutinin (FHA), pertactin (Prn), tetanus toxoid (TT), and diphtheria toxoid (DT) were measured using commercially available enzyme-linked immunosorbent assays (ELISA).
  
  
  RESULTS
  One month after the booster dose, significantly lower antibody titers were measured in the Tdap group for anti-TT IgG (P < .001) only. Anti-DT IgG, anti-PT IgG, anti-Prn IgG, and anti-FHA IgG antibody titers were comparable for both groups. A rise in antibody concentrations was elicited for all (except DT) antigens after boosting.
  
  
  CONCLUSIONS
  The present results indicate that the blunting of infant pertussis responses induced by maternal immunization, measured after a primary series of aP vaccines, was resolved with the booster aP vaccine dose. These results add to the evidence for national and international decision makers on maternal immunization as a vaccination strategy for protection of young infants against infectious diseases.
authors.affiliation: Centre for the Evaluation of Vaccination, Vaccine and Infectious Diseases Institute, University of Antwerp, Belgium.
authors.forename: Kirsten
authors.initials: K
authors.lastname: Maertens
authors.affiliation: Bacteriology Department, National Institute of Hygiene and Epidemiology, Hanoi, Vietnam.
authors.forename: Thi Thu Ha
authors.initials: TT
authors.lastname: Hoang
authors.affiliation: Bacteriology Department, National Institute of Hygiene and Epidemiology, Hanoi, Vietnam.
authors.forename: Trung Dac
authors.initials: TD
authors.lastname: Nguyen
authors.affiliation: National Reference Centre Bordetella, National Reference Centre Toxigenic Corynebacteria, Service Immunology, Scientific Institute of Public Health, Brussels.
authors.forename: Raïssa Nadège
authors.initials: RN
authors.lastname: Caboré
authors.affiliation: Bacteriology Department, National Institute of Hygiene and Epidemiology, Hanoi, Vietnam.
authors.forename: Thi Hong
authors.initials: TH
authors.lastname: Duong
authors.affiliation: National Reference Centre Bordetella, National Reference Centre Toxigenic Corynebacteria, Service Immunology, Scientific Institute of Public Health, Brussels.
authors.forename: Kris
authors.initials: K
authors.lastname: Huygen
authors.affiliation: Interuniversity Institute for Biostatistics and Statistical Bioinformatics, Hasselt University.|Centre for Health Economics Research and Modeling Infectious Diseases, Vaccine and Infectious Disease Institute, University of Antwerp, Belgium.
authors.forename: Niel
authors.initials: N
authors.lastname: Hens
authors.affiliation: Centre for the Evaluation of Vaccination, Vaccine and Infectious Diseases Institute, University of Antwerp, Belgium.
authors.forename: Pierre
authors.initials: P
authors.lastname: Van Damme
authors.affiliation: Bacteriology Department, National Institute of Hygiene and Epidemiology, Hanoi, Vietnam.
authors.forename: Duc Anh
authors.initials: DA
authors.lastname: Dang
authors.affiliation: Centre for the Evaluation of Vaccination, Vaccine and Infectious Diseases Institute, University of Antwerp, Belgium.
authors.forename: Elke
authors.initials: E
authors.lastname: Leuridan
mesh_terms: D000328:Adult; D000907:Antibodies, Bacterial / Q000097:blood / Q000276:immunology; D005260:Female; D006801:Humans; D007117:Immunization, Secondary; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D018811:Maternal Exposure; D010567:Pertussis Vaccine / Q000008:administration & dosage / Q000276:immunology*; D011159:Population Surveillance; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D014611:Vaccination; D014744:Vietnam / Q000453:epidemiology; D014917:Whooping Cough / Q000453:epidemiology / Q000517:prevention & control*
chemical_list: D000907:Antibodies, Bacterial; D007074:Immunoglobulin G; D010567:Pertussis Vaccine
keywords: maternal antibodies; pertussis; vaccination in pregnancy