Dogma Virus

The Dogma Virus was a virus created by the Free Time organisation, under the direction of the Daleks. (AUDIO: Panacea, Ascension)

The virus infected Time Lords, but lay dormant until regeneration, at which point it would hijack their symbiotic nuclei, and the infected Time Lord would be "zombified".

The virus broke out on Gallifrey, and Romana II was faced with the choice of letting Gallifrey fall to the virus in the hope of rebuilding it with the Biodata Archive, or to administer the "cure" which would render the Time Lords unable to regenerate. (AUDIO: Panacea)

President Matthias quarantined all those infected with the virus in an attempt to cure the virus whilst Romana was away. Romana's eventual return to Gallifrey spelled the end of the virus when the biodata archive was used to restore the biology and memory of every Time Lord from back up. While cured, the months of experience that had passed since the back up were lost. Restoration also left everyone in the Capitol unconscious while their minds were reset, leaving the planet open to attack from a Dalek taskforce. (AUDIO: Ascension)