Safety of Tetanus, Diphtheria, Acellular Pertussis With 5 Acellular Pertussis Components (Tdap5) Vaccination During Pregnancy

The purpose of this study is to evaluate the safety of Adacel vaccine among pregnant individuals exposed to Adacel at any point between the 1st day of the 27th week of gestation up to the end of pregnancy and their offspring (ie, Adacel-exposed cohort), in comparison with pregnant individuals not vaccinated with any Tdap vaccines during pregnancy and their offspring (ie, Tdap-unvaccinated comparator cohort). The primary objectives are to estimate incidence rates and relative risks for each prespecified pregnancy outcome in Adacel-exposed and Tdap-unvaccinated comparator cohorts and for each prespecified adverse birth outcome in the offspring of both cohorts. The secondary objectives are to estimate incidence rates and relative risks for each prespecified adverse fetal and neonatal outcome in the offspring of Adacel-exposed and Tdap unvaccinated comparator cohorts and for each prespecified adverse outcome for pregnant individuals in both cohorts.

Study outcomes to be assessed in electronic medical records between January 2016 to December 2025.