Reminds me of Shapely from William Gibson's Bridge Trilogy
"He was discovered by the AIDS industry when he had already been HIV-positive for twelve years. His strain of HIV was notpathogenic but was able to kill the lethal strain of HIV. By isolating his mutant strain of HIV it was possible to develop an AIDS vaccine."
Hmm, I wonder how well that would work. I believe HIV mutates a lot, and so if you infected yourself with a "nonpathogenic" version, I'm not sure it would remain so forever. (Though it says "develop", so perhaps they could find or introduce some other weaknesses in that strain, and let it kill all the existing HIV, then flood the patient's body with something that kills the new strain before it can mutate.)
"He was discovered by the AIDS industry when he had already been HIV-positive for twelve years. His strain of HIV was notpathogenic but was able to kill the lethal strain of HIV. By isolating his mutant strain of HIV it was possible to develop an AIDS vaccine."