Dude, let's put it like this:
Any company which discovers a cure gets a monopoly (patent) on it for 20 years. Which is a lot.
Now picture having this choice:
A. You get the existing anti-virals which tend to do a lot of damage. (There's a reason you don't get them for a cold or even a flu: they do more damage than the flu.) And they might or might not work. In fact, you'll probably just buy you some time. And everyone makes them, so while there's some money milking potential in the "but mine work better" factor, you're still just getting a slice of the pie.
B. You get the miracle cure from Company X, which actually works and presumably with a lot less side effects.
Choice B is a no-brainer. The company which would get a 20 year monopoly on B, is going to sit on a freaking huge fortune at the end of those 20 years. Not only they'd get the lion's share of the existing pie, they'd get a whole merry bunch of retards who'd rather buy the cure later than use a condom. Again.
So basically, you're telling me that a whole lot of CEOs, doctors, their investors, etc:
1. Would rather work for the general benefit of their competitors in preserving a status quo, instead of making a metric buttload of money for themselves.
2. A lot of rich and powerful people, and some of those same CEOs, doctors, etc, would rather die themselves or watch friends and family die a slow death, than just use that supposed miracle cure.
3. Thousands to millions of underlings, who otherwise can't seem to keep much else secret, just toe the line on this one. And again, would rather be loyal to some cartel than save themselves or their friends and family in some cases. And all the retards who lose laptops, or get internal corporate networks virused, etc, lose everything _except_ this apparently. They lose customer files, they leak that their network has blank admin passwords, etc, but somehow they never manage to leak _that_.
4. Somehow the Chinese, Russians, and a fucking buttload of other governments just itching for a pretext to one-up the West, and thumb their nose at the West, also toe that line peacefully. And, you know, all the retards like those in South Africa and various other countries, peddling sweet potato juice and other local snake oil as cures for HIV and as a substitute for paying to the big pharma for a cure, don't just go ahead and and make that miracle cure.
Remember: if it's secret, then it's also not patented. Patents tell everyone that it exists, so they don't work well for a conspiracy.
Etc, etc, etc.
And the same goes for diabetes, cancer, and all the other poster cases used by such conspiracy theories. In fact, for a lot of them half the points above go double. (E.g., insulin is out of patent, and it's a commodity produced by everyone, so profit margins are tiny. Plus you have local factories which don't pay big pharma a cent. So patenting a cure would make a lot of people very very rich. E.g., cancer doesn't really have as easy a defense as using a condom, and as other diseases go down and life expectancy rises, so does the chance that you'll live enough to get a cancer. So that one requires literally believing that the millions of doctors, researchers, pharma bigwigs, etc, would rather die of it and do something as brutal as radiotherapy or chemotherapy, instead of using the miracle cure. Etc.)
So here's an idea: noone understands that conspiracy theory, because it's fucking stupid even as conspiracy theories usually go. It doesn't require even just delusions and or building whole rationales on silly suppositions instead of facts. It requires genuine inability to follow even elementary logic.