The viral weapon was a biogenic weapon used by the photonic insurgency against the Lokirrim. The weapon targeted the cerebral cortex, causing synaptic failure within days. Though there was no cure, the progress of the virus could be slowed with a neural inhibitor. In 2377, the Lokirrim accused the crew of the Delta Flyer II of manufacturing viral weapons, after discovering biomatter onboard that the Doctor had been studying. (VOY: "Body and Soul")