Polypeptides and other compounds that can bind specifically to the CH2-CH3 cleft of an immunoglobulin molecule, as well as methods for using such polypeptides and compounds to inhibit Fc-mediated immune complex formation in viral infection, I are described. For example, polypeptides and other compounds can be used to inhibit immune complex formation in a subject who has been diagnosed as having or is suspected of having an Ebola virus infection, a subject who has been diagnosed as having or is suspected of having an influenza virus infection, or a subject who has been diagnosed as having or is suspected of having a hepatitis virus infection.
