Virology (HIV, HepBsAg, HepC) unless known negative within previous 2 months. 8. Urinalysis (dipstick and microscopy). 9. Bone scan , if not performed within 3 months of the start of screening. 10. CT scan with contrast* (abdomen and pelvis) if not performed within 3 months of the start of screening. *For subjects with allergies to contrast agents, MRIs for abdomen and pelvis may be performed. Only in cases where MRI is unavailable may a non - contrast CT be performed. For subjects enrolled in Germany, MRI must be used as the primary imaging modality. 7.2 Day 1 (Day of first dose of PROSTVAC -V/F or placebo), Week 1 Subjects must be randomized and the first dosing date entered and confirmed in IVRS prior to any Week 1 procedures being performed. Treatment assignment must be obtained through IVRS prior to dosing. During Week 1 of the Treatment phase of this study, the following procedures will be performed and dosing will occur as follows To be performed PRIOR to administration of study drug: 1. Adverse events (AEs) should be sought by non - directive questioning of the subject, self -reported, and/or directly observed at each clinic visit during the treatment phase of the study. 2.