In 2175 humans were devastated by the Mosquito virus, a contaminant from outer space. Serendipitously, scientists at Clone-a-Cat discovered that a transposon in the DNA of a genetically engineered cat called Azz-Lex, could neutralise the Amora virus. Implantation of the ‘Azz-Lex transposon’ became the miracle cure that saved humankind.
Treatment did, however, lead to people who periodically chewed grass and vomited or needed to squat on sand to pee. Absolutely everyone wanted to be waited on hand and foot, eat or sleep, so nothing ever got done.
It was much better than dying unless of course, you were a dog.