Disclosed are methods of treating, inhibiting, or preventing a viral infection in a mammal in need thereof by administering a therapeutically or prophylactically effective amount of an inhibitor of FAP, an inhibitor of DPPIV, an inhibitor of DPP8, or an inhibitor of DPP9. The inhibitor may act as both an inhibitor of DPPIV and an inhibitor of DPP8/9. The viral infection includes, but is not limited to, hepatitis B virus, hepatitis C virus, human immunodeficiency virus, Polio virus, Coxsackie A virus, Coxsackie B virus, Rhino virus, respiratory syncytial virus, dengue virus, equine infectious anemia virus, Echo virus, small pox virus, Ebola virus, and West Nile virus.
