Association of Maternal Tdap Recommendations With Pertussis Hospitalizations of Young Infants.

BACKGROUND: It is well established that young infants have the highest risk of severe pertussis, which often results in hospitalization. Since the 2012 recommendation of administering tetanus toxoid, diphtheria toxoid, and acellular pertussis (Tdap) vaccine for every pregnancy, evaluation of pertussis hospitalizations among young infants in the United States has been limited. METHODS: In this ecological study, we used the Kids' Inpatient Database, the largest all-payer pediatric inpatient database in the United States, to study pertussis hospitalizations among infants <1 month of age from 2000 to 2016. RESULTS: The overall rate of pertussis hospitalizations before the Tdap vaccination recommendation was 5.06 per 100 000 infants (95% confidence interval, 4.36-5.76) and 2.15 per 100 000 infants (95% confidence interval, 1.49-2.81) afterward. CONCLUSIONS: This study supports maternal vaccination against pertussis as an important strategy in protecting young infants, and continued evaluation is needed to assess the long-term trends in hospitalization.