The present invention relates to compounds and methods for the prevention or treatment of infections by negative strand RNA viruses, such as influenza virus and measles virus, wherein said compounds delay or inhibit viral replication by modulating the level or activity of a polypeptide involved in the synthesis or degradation of sphingosine-1-phosphate (S1P) in a cell, tissue, or subject. The methods involve administration of one or more compounds which modulate the level of gene expression, where the gene encodes a polypeptide involved in regulating the metabolic level of S1P, or modulate the level or activity of a polypeptide involved in regulating the metabolic level of S1P, such as sphingosine kinase (SK) and S1P lyase (SPL). Exemplary methods are directed towards reducing the level of SW by reducing the level or activity of one or more SKs, increasing the level or activity of one or more SPLs, or a combination of both steps.
