Background: Existing ethics guidance and regulatory requirements emphasize the need for pregnancy-specific safety and efficacy data during the development of vaccines in health emergencies. Our objective was to conduct a systematic review of vaccine clinical trials during active epidemic periods.
Methods: We searched for Phase II and Phase III vaccine clinical trials initiated during the H1N1 influenza, Middle East Respiratory Syndrome Coronavirus (MERS-CoV), Zika, and Ebola virus disease (EVD) outbreaks from 2009 to 2019.