E.W. "Al" Thrasher
Status: Funded - Open
Efficacy and immunogenicity of Tdap immunization of pregnant women for preventing pertussis in early infancy
Saad Omer, MBBS, MPH, PhD
BACKGROUND: Despite routine childhood vaccination against pertussis for more than six decades, pertussis remains endemic throughout the world. Infants too young to be completely vaccinated are a high-risk group for acquiring pertussis resulting in severe and life-threatening complications.
GAP: 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. However, there are limited data in developing country setting on the impact of mother-to-infant antibody transfer, including whether that translates to efficacy to prevent or ameliorate infant pertussis and whether it attenuates infant pertussis immunization.
HYPOTHESIS: Following maternal vaccination with Tdap in the third trimester of pregnancy (Tdap vaccination at 27-36 weeks of gestation) there will be an efficient transfer of antibodies between women and their infants and no significant attenuation of infants’ antibody response to childhood pertussis vaccine. Maternal vaccination with Tdap will reduce pertussis in infants up to 6 months of age.
METHODS: The proposed study is a randomized, blinded, controlled, phase III vaccine field implementation trial of maternal Tdap vaccination during the third trimester of pregnancy. The study will be conducted in Quetzaltenango in western Guatemala.
IMPACT: Better understanding of infant effects of maternal pertussis immunization could provide an important tool to combat pertussis disease in early infancy, particularly in developing countries. Evidence from the proposed trial could inform the policy to replace TT and Td with Tdap globally.
Pregnancy, Pertussis, Vaccine, Treatment, Human, Randomized Clinical Trial
United States, Guatemala