Maternal Tdap Immunization in Guatemala

Overview

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.

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 and serious adverse events will also be monitored.