The subject invention provides materials and methods for treating various health conditions, including the prevention and/or treatment of a viral infection. In a preferred embodiment, a cysteamine compound is administered to a subject to treat an influenza virus infection. More preferably, a cysteamine compound is administered to a subject to treat influenza A, influenza B, influenza C virus infections, including avian influenza virus subtypes (such as H5N1 avian influenza virus).