title: Influence of maternal vaccination against diphtheria, tetanus, and pertussis on the avidity of infant antibody responses to a pertussis containing vaccine in Belgium.
abstract: Maternal antibodies induced by vaccination during pregnancy cross the placental barrier and can close the susceptibility gap to pertussis in young infants up to the start of primary immunization. As not only the quantity but also the quality of circulating antibodies is important for protection, we assessed whether maternal immunization affects the avidity of infant vaccine-induced IgG antibodies, in the frame of a prospective clinical trial on pregnancy vaccination in Belgium. Infants born from Tdap (Boostrix®) vaccinated (N = 55) and unvaccinated (N = 26) mothers were immunized with a hexavalent pertussis containing vaccine (Infanrix Hexa®) at 8, 12 and 16 weeks, followed by a fourth dose at 15 months of age. Right before and one month after this fourth vaccine dose, the avidity of IgG antibodies against diphtheria toxin (DT), tetanus toxin (TT), pertussis toxin (PT), filamentous hemagglutinin (FHA) and pertactin (Prn) was determined using 1.5 M ammonium thiocyanate as dissociating agent. In both groups, antibody avidity was moderate for TT, PT, FHA and Prn and low for DT after priming. After a fourth dose, antibody avidity increased significantly to high avidity for TT and PT, whereas it remained moderate for FHA and Prn and low for DT. The avidity correlated positively with antibody level in both study groups, yet not significantly for PT. When comparing both study groups, only PT-specific antibodies showed significantly lower avidity in infants born from vaccinated than from unvaccinated mothers after the fourth vaccine dose. The clinical significance of lower avidity of vaccine induced infant antibodies after maternal vaccination, if any, needs further investigation.
authors.affiliation: a National Reference Centre for Bordetella & National Reference Centre for Toxigenic Corynebacteria , Scientific Service Immunology, Scientific Institute of Public Health (WIV-ISP) , Brussels , Belgium.
authors.forename: Raïssa Nadège
authors.initials: RN
authors.lastname: Caboré
authors.affiliation: b Centre for the Evaluation of Vaccination , Vaccine & Infectious Diseases Institute, University of Antwerp , Antwerp , Belgium.
authors.forename: Kirsten
authors.initials: K
authors.lastname: Maertens
authors.affiliation: c Scientific Service Biological Standardisation , Scientific Institute of Public Health (WIV-ISP) , Brussels , Belgium.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Dobly
authors.affiliation: b Centre for the Evaluation of Vaccination , Vaccine & Infectious Diseases Institute, University of Antwerp , Antwerp , Belgium.
authors.forename: Elke
authors.initials: E
authors.lastname: Leuridan
authors.affiliation: b Centre for the Evaluation of Vaccination , Vaccine & Infectious Diseases Institute, University of Antwerp , Antwerp , Belgium.
authors.forename: Pierre
authors.initials: P
authors.lastname: Van Damme
authors.affiliation: a National Reference Centre for Bordetella & National Reference Centre for Toxigenic Corynebacteria , Scientific Service Immunology, Scientific Institute of Public Health (WIV-ISP) , Brussels , Belgium.
authors.forename: Kris
authors.initials: K
authors.lastname: Huygen
mesh_terms: D000328:Adult; D000907:Antibodies, Bacterial / Q000276:immunology*; D000915:Antibody Affinity; D000917:Antibody Formation; D001530:Belgium; D004165:Diphtheria / Q000276:immunology* / Q000517:prevention & control; D015721:Diphtheria-Tetanus-Pertussis Vaccine / Q000008:administration & dosage* / Q000276:immunology; D005260:Female; D006801:Humans; D007112:Immunity, Maternally-Acquired; D007223:Infant; D007231:Infant, Newborn; D007232:Infant, Newborn, Diseases / Q000276:immunology / Q000382:microbiology / Q000517:prevention & control*; D008297:Male; D011247:Pregnancy; D011248:Pregnancy Complications / Q000276:immunology* / Q000382:microbiology; D011446:Prospective Studies; D013742:Tetanus / Q000276:immunology* / Q000517:prevention & control; D014611:Vaccination; D014917:Whooping Cough / Q000276:immunology / Q000517:prevention & control; D055815:Young Adult
chemical_list: D000907:Antibodies, Bacterial; C505143:Boostrix; D015721:Diphtheria-Tetanus-Pertussis Vaccine
keywords: avidity; diphtheria; infant; maternal vaccination; pertussis; tetanus; vaccine