Panucci G, Chada K, Izurieta H, Shoaibi A, Said M, Forshee R, Obidi J, Petrone A, Cocoros N, Woodworth T, Kawai AT. Trends of tetanus, diphtheria, and acellular pertussis (Tdap) vaccination during pregnancy in the Sentinel System. Poster presented at the 33rd ICPE International Conference on Pharmacoepidemiology & Therapeutic Risk Management; August 2017. Montreal, Canada. [abstract] Pharmacoepidemiol Drug Saf. 2017 Aug; 26((Suppl. 2)):414.

BACKGROUND: Since 2011, Centers for Disease Control and Prevention has recommended that women receive Tdap vaccination during pregnancy to minimize the significant burden of pertussis on infants. Prior to 2011, CDC recommended immediate postpartum Tdap vaccination. The Sentinel System’s Post-Licensure Rapid Immunization Safety Monitoring (PRISM) program, established in response to the 2007 FDA Amendments Act to monitor the safety of FDA-regulated medical products, was used to estimate Tdap vaccination use among pregnant women.

OBJECTIVE: To assess the Sentinel System’s ability to identify Tdap vaccine exposures in pregnant women

METHODS: We identified a cohort of pregnant women ages 10 to 55 years using electronic health plan data from six Sentinel Data Partners. Pregnancies ending in a live delivery from 2010 to 2015 were identified using a validated algorithm that incorporated diagnosis and procedure codes. Tdap vaccinations that occurred during pregnancy or immediately postpartum during the delivery visit were identified using procedure codes.

RESULTS: We identified over 2.6 million live birth pregnancies, of which 15.5% (n=407,879) had a Tdap vaccination during pregnancy and 3.2% (n=84,172) had a Tdap vaccination during the delivery visit. The proportion of Tdap vaccination during pregnancy increased substantially overtime, from 0.8% for deliveries in 2010 to 38.8% for deliveries in 2015, with the largest increases from 2011 to 2012 and 2012 to 2013. By contrast, the proportion of Tdap vaccination during delivery visits remained low and relatively stable over time, with slight decreases from 2012 to 2015.

CONCLUSIONS: Trends of Tdap vaccination during pregnancy in the Sentinel population increased substantially in the years following the 2011 CDC recommendation, which is consistent with results from other studies of commercially insured women. This study demonstrated the feasibility of identifying vaccine exposures in pregnant women, which could facilitate vaccine safety or effectiveness surveillance using Sentinel’s PRISM program. Mother-child linkages and characterization of other data elements would also be needed to conduct these vaccine surveillance activities.