Adverse events in pregnant women following administration of trivalent inactivated influenza vaccine and live attenuated influenza vaccine in the Vaccine Adverse Event Reporting System, 1990-2009

Abstract

The objective of the study was to characterize reports to the Vaccine Adverse Event Reporting System (VAERS) in pregnant women who received seasonal influenza vaccines to assess for potential vaccine safety concerns. We searched VAERS for reports of adverse events (AEs) in pregnant women who received trivalent inactivated influenza vaccine (TIV) from July 1, 1990 through June 30, 2009, or live attenuated influenza vaccine (LAIV) from July 1, 2003, through June 30, 2009. A total of 148 reports after TIV and 27 reports after LAIV were identified. Twenty TIV (13.5%) and 1 LAIV (4%) reports were classified as serious. No specific AEs were reported in 30 TIV (20.3%) and 16 LAIV (59%) reports. The most common pregnancy-specific AE was spontaneous abortion: 17 after TIV (11.5%) and 3 after LAIV (11%). The reporting rate of spontaneous abortion was 1.9 per million pregnant women vaccinated. No unusual patterns of pregnancy complications or fetal outcomes were observed in the VAERS reports of pregnant women after the administration of TIV or LAIV.