Clinical Trial: Maternal Tdap Immunization in Guatemala

Study Status: Recruiting
Recruit Status: Recruiting
Study Type: Interventional

Official Title: Evaluation of Tdap in Pregnancy to Prevent Infant Pertussis

Brief Summary: Maternal immunization with tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccine (Tdap) is a potential strategy to protect young infants against pertussis before they are fully vaccinated because maternal antibodies may cross the placenta and passively protect her infant. The proposed study is a randomized, blinded, controlled, vaccine trial of maternal Tdap vaccination during the third trimester of pregnancy (Tdap vaccination at 27-36 weeks gestation). Pregnant women will be recruited from the prenatal care clinics at the Hospital Nacional Occidente and the Health Centers in Quetzaltenango, La Esperanza, San Juan Ostuncalco and Concepción Chiquirichapa. Enrolled women and their infants will be followed up until 7 months post-partum.

Detailed Summary:

The proposed study is a randomized, blinded, controlled, vaccine trial of maternal Tdap vaccination during the third trimester of pregnancy (Tdap vaccination at 27-36 weeks gestation). Pregnant women will be recruited from the prenatal care clinics at the Hospital Nacional de Occidente and the Health Centers in Quetzaltenango, La Esperanza, San Juan Ostuncalco and Concepción Chiquirichapa.

All healthy pregnant women between the ages of 18 and 40 years (inclusive) at 27 weeks gestation or later who are in the study areas will be eligible to participate in this study unless they meet one or more of the exclusion criteria. Pregnant women at <27 weeks gestation will be pre-screened and provided information about the study to encourage them to enroll later in their pregnancy. Women who are eligible will be enrolled after obtaining informed consent, and then they will be randomized to receive Tdap vaccine or Td vaccine. Enrolled women and their infants will be followed up until 7 months postpartum.

To address the primary objective, serum specimens will be collected from mothers prior to receiving the study product (Tdap or Td), within 72 hours after delivery and at 7 months post-partum. Moreover, infants specimens will be collected at delivery (cord blood or infant blood within 72 hours of birth), at 2 months of age (prior to the first dose of the routine childhood DTwP series), and at 7 months of age (approximately 4 weeks after the third dose of the routine DTwP series).

Infants will be given all three doses of the pentavalent vaccine which includes DTwP vaccine at 2, 4 and 6 months (routine childhood immunizations) as recommended by the immunization schedule of Guatemala's National Immunization Program.

Adverse events a
Sponsor: Emory University

Current Primary Outcome:

  • Infant pertussis antibody geometric mean concentrations (GMC) and 95% confidence intervals at birth (cord blood OR infant blood within 72 hours of birth), at 2 months of age, and 7 months of age [ Time Frame: Birth to 7 months of age ]
  • Ratio of infant to mother pertussis antibody levels at the time of delivery [ Time Frame: Birth to 7 months of age ]
  • Proportion of infants with at least a four-fold rise in serum antibody titer between 2 months and seven months of age (i.e., at four weeks after the 3rd dose of childhood DTwP) [ Time Frame: Birth to 7 months of age ]
  • Maternal pertussis antibody GMC and 95% confidence intervals at baseline (pre-vaccination), within 72 hours after delivery, and seven months post-partum [ Time Frame: Pre-vaccination to 7 months post-partum ]
  • Proportion of mothers sero-converting (serum pertussis antibody titer increase of ≥ 4-fold compared to pre-vaccination antibody levels) and 95% confidence intervals at the time of delivery (within 72 hours after delivery) and seven months post-partum [ Time Frame: Pre-vaccination to 7 months post-partum ]


Original Primary Outcome: Same as current

Current Secondary Outcome:

  • Incidence of illnesses meeting the syndromic case definition (defined below); prematurity; pneumonia (per WHO Integrated Management of Childhood Illness [IMCI] classification) [ Time Frame: Birth to 7 months of age ]
  • Birth weight and infant growth/anthropometric measurements (e.g., height and weight for age). [ Time Frame: Birth to 7 months of age ]
  • Incidence of unsolicited non-serious (grades 1 & 2) adverse events 7 days post-delivery (for neonates) [ Time Frame: Birth to 7 months of age ]
  • Infant growth/anthropometric measurements (e.g., height and weight z-scores at birth and 7 months of age) [ Time Frame: Birth to 7 months of age ]
  • Incidence of serious (grades 3 & 4) adverse events through 7 months of age [ Time Frame: Birth to 7 months of age ]
  • Laboratory (real-time PCR) confirmed pertussis infection in infants younger than 6 months of age [ Time Frame: Birth to 7 months of age ]
  • Incidence of unsolicited non-serious (grades 1&2) AEs 28 days post vaccination [ Time Frame: Pre-vaccination to 7 months post-partum ]
  • Incidence of serious (grades 3 & 4) adverse events through 7 months post-partum [ Time Frame: Pre-vaccination to 7 months post-partum ]


Original Secondary Outcome: Same as current

Information By: Emory University

Dates:
Date Received: November 22, 2014
Date Started: July 2016
Date Completion: July 2018
Last Updated: August 15, 2016
Last Verified: August 2016