Dramian Plague

Of unknown origin, the plague on Dramia II in 2251 was characterized by pigmentation changes in the skin of its victims, followed by debilitation and death. The plague caused the Dramian skin to change from its traditional yellow hue to blue, then green, and finally, to red. In 2270, the Enterprise crew is unknowingly infected with the plague, and all but Mister Spock are debilitated. Vulcans are immune to the disease, so Spock is able to break Doctor McCoy out of a Dramian prison, and return him to the Enterprise. There, they surmise that the color changes are actually effects from a color-changing aurora nearby, and McCoy creates an antidote for the plague from antibodies to the Saurian virus.