Surveillance of Maternal Tetanus Toxoid, Reduced Diphtheria Toxoid, and Acellular Pertussis (Tdap) Vaccines in the Vaccine Adverse Event Reporting System-United States, July 1, 2015-September 30, 2023.

OBJECTIVE

To assess the safety of tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccine in pregnant women in the United States using data from the Vaccine Adverse Event Reporting System (VAERS).

DESIGN,

SETTING

We searched VAERS for reports of Tdap in pregnant women vaccinated during July 2015 through September 2023. We reviewed reports and available medical records for pregnancy and non-pregnancy specific adverse events (AEs) in Tdap recipients. Reporting rates were estimated for reports of preterm birth, hypertensive disorders of pregnancy (HDP), and stillbirths and compared to published background rates for these conditions.

RESULTS

VAERS received a total of 654 reports after Tdap vaccine in pregnancy and 137 (20.9%) were serious; no maternal or infant deaths were reported. The most common pregnancy specific conditions reported were preterm birth (45, 6.9%), hypertensive disorders of pregnancy (40, 6.1%), and stillbirth (18, 2.8%). Two reports of verified Guillain-Barré Syndrome (GBS) were reported. The most common non-pregnancy specific conditions reported were pain (120, 18.3%), nausea (93, 14.2%), and fever (87, 13.3%). Reporting rates for preterm birth, HDP, and stillbirths were below background rates for these conditions.

CONCLUSION

Most reports were non-serious and the most common AEs were similar to those observed in pre- and post-licensure studies. No new or unexpected AE was identified.