We disclose here a method for using Poly-ICLC to prevent and/or treat certain human and veterinary infectious, neoplastic and autoimmune disorders, as well as for regulating a broad variety of genes in humans, consisting of use of poly-ICLC repeatedly and at low doses, alone or in combination with other drugs or vaccines. As such it represents an example of broad spectrum host-targeted therapeutics, in contrast to conventional antibiotics, antiviral or antineoplastic agents that target specific organisms or tumors.