What if the AIDS virus isn't a virus at all. What if It's actually a parasite. An alien parasite that is as smart as humans. It just floats around and fucks with the human body by outsmarting it. Then it will become the dominant species on earth and rule mankind with an iron fist .
In case you haven't figured out, these theories are probably full of bullshit and plot holes that make this not make sense. These have almost no chance of being true, and are wild guesses, so don't read into it. But do add your own input, if you have any.