Provided are processes for the prevention or treatment of viral infection in a subject. Some aspects provide administration of a sphingoid compound, optionally sphingosine, an active ingredient that activates generation of a sphingoid base, optionally of sphingosine; or an active agent that inhibits the degradation of a sphingoid base, optionally of sphingosine, to a subject such as a human. By increasing the local concentration of sphingosine in a subject or an area of a subject to which the composition is administered such as the nose or interior of the nose or portion thereof, the ability of viruses to infect the subject or cells thereof is reduced thereby treating of preventing infection by the virus.