HIV is a legitimately difficult problem. Thousands of very smart people have devoted the last 30 years to studying every gene, protein, and molecule in the virus and have created more models than any disease other than cancer. I spent two hours sitting with an undergrad who asked me “Well… why didn’t they try [X] then?” and I had an answer ready for them. Nearly everything has been tried against HIV and unless people invent a class of drugs (which does happen on a periodic basis), our current tools aren’t going to work.
People have to recognize what HIV is. It’s a lipid-encapsulated ss-RNA retrovirus that works by invading the T-cells, the very cells that our immune system relies on to respond to viral infections.
There is one and only one viral protein target on the outside and that is the env protein which is a bitch of a protein to target. It’s coated with sugars and the only conserved domains are hidden in the core. Antibody responses rarely block a meaningful site on the protein. In a cohort study of 4,484 patients selected from a pool of 18,489 individuals, only 239 generated antibodies that did anything. Of that group, only 19 produced antibodies against the GP41 domain.
The structure of this protein is coated with glycans (shown in green) which protect the protein. Only when the env protein is bound to its target of CD-4, do the conserved regions expose themselves (in white). Targeting HIV is like waiting for a suicide bomber to take out the trigger to identify the bad guy.
That’s assuming that we can even find the virus in the first place. HIV can lie dormant in reservoirs in CD4+ T-cells for decades and patients who have no signs of HIV for years can suddenly have an outbreak of the virus. Only 1 in 1 million T-Cells will contain latent HIV.
In summary, finding an actual cure for HIV is a bitch. Believe me, people have tried. But until someone comes up with a special nanobot that can individually search through 1 million T-cells, pull out the virus and then bind to the one conserved spot on the bug, we’re not going to get a “cure” for a while.
But that’s not going to stop people from trying. See the answers over at What are the most promising treatments in development for HIV?