Methods for purifying virus preparations are disclosed comprising (a) subjecting a virus preparation to anion-exchange chromatography, (b) adding a polyhydroxy hydrocarbon to the virus preparation of step (a), (c) increasing the concentration of virus in the virus preparation product of step (b) by applying pressure to the preparation such that diluent is removed from the virus preparation through a filter, and (d) subjecting the concentrated virus preparation product of step (c) to one or more additional processing steps.