The multiphasic prion was a pathogen that infected Humans and could be potentially life-threatening. The prions initially attached themselves to the mitochondrial wall, and later migrated to the cell membranes and ruptured them. One of the early symptoms of infection was a slight elevation in body temperature.

Crewman William Telfer, a hypochondriac, thought he had a multiphasic prion infection before his first away mission in 2376. (VOY: "Good Shepherd")