Viruses

YF-ZIKprM/E is a derivative of the YFV-17D vaccine expressing an Asian-lineage ZIKV prM/E envelope [13]. YFV-17D-Nluc is a YFV-17D derivative with a Nanoluciferase reporter gene cassette inserted into the YFV-17D polyprotein downstream of codon 22. The construction of YFV-17D-Nluc is described elsewhere (Schmid et al, manuscript in preparation). Working stocks of YFV-17D were generated by passaging Stamaril® (Sanofi-Pasteur MSD, Brussels, lot H5105) purchased from the pharmacy of the University Hospital Leuven once on BHK-21J cells and twice on Vero E6 in 2% FBS MEM. Supernatants were harvested when virus-induced cytopathic effect became evident, cleared by centrifugation (3000 g for 10 min) and stored at −80°C.