YF-VAX® (Sanofi, Swiftwater, PA), a live, attenuated vaccine based on the yellow fever (YF) substrain 17D-204, is the only YF vaccine licensed in the USA. Manufacturing disruption of YF-VAX and anticipated depletion of the US supply by mid-2017 led to the importation of another YF vaccine, STAMARIL® (Sanofi, France), into the USA under an expanded access investigational new drug program (EAP) to fulfil the public health need for YF vaccination. As part of this program, Sanofi collected enhanced safety surveillance data following vaccination with STAMARIL. Here, we report the results of the enhanced safety surveillance.