Safety of 9-valent human papillomavirus vaccine administration among pregnant women: Adverse event reports in the Vaccine Adverse Event Reporting System (VAERS), 2014-2017

Abstract

Introduction: 9-valent human papillomavirus vaccine (9vHPV) was approved by the Food and Drug Administration (FDA) in December 2014. 9vHPV is not recommended during pregnancy, but some women of childbearing age may be inadvertently exposed. This study aims to evaluate reports submitted to the Vaccine Adverse Event Reporting System (VAERS) of pregnant women exposed to 9vHPV.

Methods: We searched the VAERS database, a national post-licensure vaccine safety surveillance system, for reports of pregnant women vaccinated with 9vHPV in the United States between December 10, 2014 and December 31, 2017. Disproportionate reporting of adverse events (AEs) was assessed using proportional reporting ratios (PRRs).

Results: A total of 82 pregnancy reports were identified. Sixty reports (73.2%) did not describe an AE and were submitted only to report the vaccine exposure during pregnancy. The most frequently reported pregnancy-specific AE was spontaneous abortion (n = 3; 3.7%), followed by vaginal bleeding (n = 2; 2.4%). Among non-pregnancy-specific AEs, injection site reaction (n = 3; 3.7%) was most common. No disproportionate reporting of any AE was found.

Discussion: No unexpected AEs were observed among these pregnancy reports.

Keywords: Adverse event; Epidemiology; Human papillomavirus vaccine; Surveillance; Vaccine safety.