Acquired Immune Deficiency Syndrome, or "AIDS," is a disease that throws entire populations into panic. It's sexually transmitted, assuredly fatal, and rather miserable to have. I had to endure many public services about it in school, because it wigged people out so severely that the department of education felt compelled to step in to inform us that no, you cannot get it from toilet seats, or handshakes, or really anything that doesn't involve other people's bodily fluids going into you.
AIDS is caused by a retrovirus, HIV. (Human Immunodeficiency Virus.) I know people who deny this, but they have no evidence for that belief. Retroviruses are one of the hardest to fight, because of how they work. I had to go into a bit of biology to explain this.
Our cells are made of protein, which are controlled by our DNA. To operate DNA, it's copied into RNA, which arranges proteins into complex structures, and folds them into their final shape. Most viruses are RNA-only, because they exist to endlessly replicate themselves, and try to convert your cells into virus factories. Retroviruses, however, know how to convert their RNA back into DNA, and replace chunks of your cell's DNA with its DNA, so the next time you copy that cell, you copy that virus too. Even if you purge all the viruses out of your body, the virus can reemerge from that cell, which is the scary thing about retroviruses. However, they can also be used for good. Genetic therapies exist in which a benign retrovirus is modified to inject beneficial genes into yours, and then the virus malfunctions and "dies" afterwards. (Well, it's debatable if viruses count as "alive," as they are just chunks of RNA and protein, but it malfunctions such as to be nonfunctional.)
So, AIDS is quite prevalent in some parts of the world, and immensely terrifying even in places were infection is rare. And yet, no part of the world is totally free of infection. Is there any surprise that there's an immense demand for a cure?
We've made a lot of progress, but aren't there yet. HIV has proven quite polymorphic, responding to all attempts to fight it by rearranging itself until it is immune to what we throw at it. And yet this strength is also now its biggest weakness. One can literally mutate it to death. Unfortunately this doesn't help medically, because the virus tends to reemerge from older, more effective forms, stashed away in a random cell's DNA.
Another discovery is that a small percentage of the population is immune to bubonic plague, which ravaged Europe in the 1300s. These people are also immune to AIDS, for reasons that we don't readily understand. (This mutation assuredly developed from the plague, in which the non-immune population of Europe was devastated, leaving only those unexposed or immune to reproduce.) I see no possible connection: bubonic plague is caused by a bacteria, and AIDS by a virus. There must be some sort of third-party connection, in that some aspect of the bubonic plague immunity also makes it harder, or impossible, for HIV to gain a foothold. More research is required.
So if a person with AIDS asked me for a treatment, I think I would start with a bubonic plague innoculation, and extremely agressive genetic therapy. Along with the traditional anti-viral drugs like AZT. I would hope to reconfigure their genes until the existence of retroviruses in their body is impossible. This would also mean that any children they had would not resemble them in the slightest, but it's a small price to pay in the face of miserable death.
Also, AIDS does not kill you directly. It just destroys your immune system so that the first other disease to come along rages through your body unopposed until you die.