Due to the nature of HIV itself, there will likely never be a cure for AIDS. That may sound like a harsh pronouncement, but it’s not the same as saying there will not be new strides in treatment – there will be as new things are discovered about HIV’s structure and weaknesses. And there will be new therapies that keep an HIV-positive diagnosis from being an early death sentence for many patients. There may even be research that finds ways to lower the viral load. But the virus will not be cured, and the key to ridding the human population of AIDS will still be prevention of HIV infection.
Acquired immune deficiency syndrome
AIDS is caused by the human immunodeficiency virus (HIV). As the virus replicates it destroys immune cells, eventually crippling the immune system of the infected person. Without a functioning immune system, the person experiences opportunistic infections and AIDS-defining conditions, essentially becoming ill with AIDS. This final stage of HIV infection is currently fatal and is what would be prevented by any cure for AIDS.
Resistance to treatment
HIV is so difficult to treat because the virus mutates with nearly every replication due to the viral enzyme responsible for encoding new strands having low fidelity. The strain of HIV can even change over the course of an individual's infection. Current treatments use antiviral drugs to prevent the virus from replicating, postponing the attack on the immune system that results in AIDS. However, a person who is on HIV medications cannot miss a treatment or else it gives the virus a chance to replicate, and thus to mutate and adapt, potentially resulting in a change in the treatment regimen.
The virus is now becoming resistant to the popular HAART treatment that was heralded as the end of AIDS so few years ago, even when the patient has an undetectable viral load (i.e. very few HIV particles in the blood). Individuals are becoming infected with multiple strains that benefit from various host cells, called superinfection, resulting in the need for a treatment that isn't specific, but general. A cure would have to take into account every strain in every cell in every environmental context. That would be impossible, though strides in broadly neutralizing antibodies are showing some success – though having 10% of treated patients not respond to treatment cannot be called a success in the context of discussing a cure.
HIV: The stealth virus
Another issue with curing AIDS is that, even if you clear out the HIV particles from the blood, once HIV infects a cell it can lie dormant for decades. HIV is not like other common viruses, it has reservoirs in the immune system. When an individual harboring dormant HIV, even if active HIV was cleared by a medication years before, becomes ill with something else, the common cold even, those cells will turn on and HIV will be born again. Any treatment that eliminates HIV from the body would have to be taken long enough, over the course of a lifetime, to get every viral particle. Research showed in late 2012 that some cancer drugs may help eliminate latent HIV infection, but it still is not a magic bullet.
HIV isn't the only virus like this. Chickenpox (varicella virus) can lie dormant in the basal root ganglia, nerve cells, and be reactivated under the right immune conditions to produce shingles. Hepatitis C is a chronic infection of the liver that can only be cured by a transplant. Depending on the type the individual is infected by, herpes simplex reactivates into cold sores or genital lesions under the right host conditions.
AIDS can’t be cured, only prevented
This world is full of viruses that humans have learned to live with, but now there’s one that can't be suppressed. Prevention and education is the only way.