Universal Tetanus–Diphtheria–Pertussis Vaccination During Pregnancy

Abstract

OBJECTIVE: To assess the cost effectiveness of tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccination in pregnant patients in the United States. METHODS: A decision-analytic model in TreeAge was developed to compare universal Tdap vaccination in pregnancy with no Tdap vaccination in pregnancy using a theoretical cohort of 3.66 million pregnant individuals, the approximate number of deliveries per year in the United States. Outcomes included infant pertussis infections, infant hospitalizations, infant encephalopathy cases, infant deaths, and maternal pertussis infections. All probabilities and costs were derived from the literature. Utilities were applied to discounted life expectancies at a rate of 3% to generate quality-adjusted life-years (QALYs). A strategy was considered cost effective if it had an incremental cost-effectiveness ratio of less than $100,000 per QALY. Univariable and multivariable sensitivity analyses were performed to assess the robustness of the model to changes in the baseline assumptions. RESULTS: With a baseline assumption of vaccine cost at $47.75, Tdap vaccination was cost effective at $7,601 per QALY. The vaccination strategy was associated with a decrease of 22 infant deaths, 11 infant encephalopathy cases, 2,018 infant hospitalizations, 6,164 infant pertussis infections, and 8,585 maternal pertussis infections, with an increase of 19,489 QALYs. In sensitivity analyses, the strategy was cost effective until the incidence of maternal pertussis became lower than 1.6 cases per 10,000 individuals, the cost of the Tdap vaccine was greater than $540, or previous pertussis immunity was present in more than 92.1% of pregnant individuals. CONCLUSION: In a theoretical U.S. cohort of 3.66 million pregnant individuals, Tdap vaccination during pregnancy is cost effective and reduces infant morbidity and mortality compared with no vaccination during pregnancy. These findings are especially relevant given that approximately half of individuals are not vaccinated during pregnancy and recent data have shown that postpartum maternal vaccination and cocooning strategies are ineffective. Public health strategies to encourage greater uptake of Tdap vaccination should be used to reduce the morbidity and mortality of pertussis infection.