We used Madex HP (Certisusa). Madex HP contains about 1E13 virus occlusion bodies (OB) per liter and the OBs were purified from the aqueous suspension by applying iterative washing and centrifugation cycles. The pellet was then re-suspended in ultra-pure water at pH7. After 3h of incubation at room temperature the supernatant, containing the almost pure OBs, was removed from the pellet and subjected to filtration steps through a sequence of stainless steel filters with decreasing pore sizes (20 um, 10 um, 5 um, 2 um, 0.5 m; all IDEX). To increase the concentration of CpGV to the desired 1E11 particles/ml for injection at LCLS, the suspension was subjected to centrifugation at 21,000 g, the supernatant was removed, and the pellet re-suspended. Size distribution and particle concentration was estimated using a Nanosight LM14 instrument (Malvern).
