A virus is a submicroscopic parasitic particle which infects the cells of lifeforms to replicate. Whilst viruses do contain basic genetic material, they do not form so much as a cell and rely on the cells of other organisms to survive and as such are not technically considered lifeforms themselves.
Examples of Viruses[edit | edit source]
The Romulan colony of Chetzia 3 was once home to a particularly virulent virus, to make the world safe for habitation the Romulans introduced a genetically modified plant to kill of the virus. The scheme was a success however the planet is now being overrun by the new plant. (TNG video game: Away Team)
The Ngultor use a type of virus when attacking vessels of other species. The Ngultor virus absorbs all the energy of a target starship converting it into a grey slim. This has the effect of incapacitating the ship so the Ngultor can harvest the crew with little resistance. In 2254 Doctor Phillip Boyce, science officer Spock and nurse Gabrielle Carlotti of the starship Enterprise were able to create a cure for the Ngultor virus allowing the Enterprise to escape from a Ngultor vessel. (EV comic: "Flesh of My Flesh")
In 2154 the Klingons attempted to genetically modify themselves using gene therapy based on genetic samples from human augments. One test subject was suffering from Levodian flu which combined with the gene therapy treatment to create a highly contagious and deadly new virus. The plague quickly spread to many worlds in the Empire before a cure was devolped. Whilst the deadly effects of the virus were nullified the cure could not reverse one unusual side-effect; Infected Klingons lost there cranial ridges. And as the effect was at the genetic level their children would have the same disfigurement. A cure for this particular effect was not developed until the late 23rd century. (ENT episodes: "Affliction", "Divergence")
The Heran Modality developed a genetically-engineered virus known as the Unity virus that was capable of rewriting the reproductive elements of the body to transform Humans into Herans. (TNG novel: Infiltrator)