This is a phase II, randomized, double-blind, active-controlled study to evaluate the safety, immunogenicity, and effect on infant immune responses of a single dose of Tetanus diphtheria acellular pertussis vaccine (Tdap) in pregnant women in Mali. 200 healthy pregnant women, ages 18 through 39 years, inclusive, who meet all eligibility criteria will be randomly allocated in a 2:1 ratio to receive either Tdap (BOOSTRIX) or Tetanus diphtheria toxoid (Td) at 14 0/7 weeks through 26 6/7 weeks estimated Gestational Age (GA). For the fetuses of pregnant subjects, GA will be established by ultrasound, whenever possible, in combination with date of last menstrual period (LMP), when available, and fundal height. Study duration is 21 months: approximately 2 months in the start-up period, 6 months enrolling subjects, and 13 months (3-7 months while pregnant and 6 months postpartum) from last subject vaccinated until she and her infant complete follow-up. The primary objectives of this study are: 1) to assess the safety and tolerability of a single 0.5 mL intramuscular injection of BOOSTRIX in pregnant women; 2) to assess the safety of a single maternal BOOSTRIX vaccination on the fetus and infant; 3) to assess the level of Pertussis Toxin (PT) antibody at birth among infants whose mothers received a single dose of BOOSTRIX or Td while pregnant. The secondary objectives are: 1) to assess the antibody response to BOOSTRIX vaccine antigens in pregnant women one month after receipt of BOOSTRIX, at the time of delivery, and at 6 months after delivery; 2) to compare the antibody levels of BOOSTRIX vaccine antigens at birth (cord blood) and 6 weeks of age (before receiving any infant doses of Diphtheria, Tetanus, and whole-cell Pertussis (DTwP)) in infants whose mothers received BOOSTRIX or Td during pregnancy; 3) to assess placental antibody transfer by determining the ratio of maternal and infant BOOSTRIX -specific antibody responses at delivery; 4) to assess interference with infant antibody responses to DTwP either prior to the second dose of the primary DTwP series, at approximately 10 weeks of age (in 1/2 of subjects), or approximately one month after the third dose of the primary DTwP series, at approximately 18 weeks of age (in 1/2 of subjects), and at 6 months of age (all subjects).
This is a phase II, randomized, double-blind, active-controlled study to evaluate the safety, immunogenicity, and effect on infant immune responses of a single dose of Tetanus diphtheria acellular pertussis vaccine (Tdap) in pregnant women in Mali. 200 healthy pregnant women, ages 18 through 39 years, inclusive, who meet all eligibility criteria will be randomly allocated in a 2:1 ratio to receive either Tdap (BOOSTRIX) or Tetanus diphtheria toxoid (Td) at 14 0/7 weeks through 26 6/7 weeks estimated Gestational Age (GA). For the fetuses of pregnant subjects, GA will be established by ultrasound, whenever possible, in combination with date of last menstrual period (LMP), when available, and fundal height. Study duration is 21 months: approximately 2 months in the start-up period, 6 months enrolling subjects, and 13 months (3-7 months while pregnant and 6 months postpartum) from last subject vaccinated until she and her infant complete follow-up. The primary objectives of this study are: 1) to assess the safety and tolerability of a single 0.5 mL intramuscular injection of BOOSTRIX in pregnant women; 2) to assess the safety of a single maternal BOOSTRIX vaccination on the fetus and infant; 3) to assess the level of Pertussis Toxin (PT) antibody at birth among infants whose mothers received a single dose of BOOSTRIX or Td while pregnant.