Vaccinating pregnant women with Tdap vaccine protects infants from pertussis and provides additional protection in their first year

A large study in California involving nearly 150,000 newborns found that vaccinating pregnant women with the Tdap vaccine provided 91% protection against pertussis infection among infants under 2 months of age and 88% protection before the infants had any vaccinations. The study also showed that vaccinating mothers during their pregnancy did not reduce the effectiveness of infant vaccination but that maternal Tdap vaccination provided additional protection to the infants through their first year of life.