The present invention relates to a method using fibrinogen-coated albumin spheres for treating a patient infected with a hemorrhagic virus. A suspension of protein nanoparticle containing submicron protein spheres is prepared and administered to the patient. The protein spheres are bound with fibrinogen molecules in vitro or in vivo. The fibrinogen-coated albumin spheres provide improved hemostatic function of a residual concentration of platelets of the patient resulting in decreasing mortality rate or decreasing morbidity of the patient. The fibrinogen-coated albumin spheres protect an endothelial function of an endothelial cell of a blood vessel of the patient resulting in improved permeability control across predetermined tissues in the patient, thereby counteracting an effect of the hemorrhagic virus on a wall of the blood vessel.
