A discovery from The University of Rochester is likely to make the whole fighting AIDS thing easier: We've been doing it wrong.
Viruses usually replicate by stealing a molecule from your cell, dNTP, and interfering with this process is the first means by which most anti-viral drugs work. AIDS, however, has taken to preying on immune cells that don't have this chemical. The university discovered that AIDS instead takes a similar molecule, rNTP, and works from there.
This could lead to whole new classes of AIDS fighting drugs, ones that do actual damage to the virus's metabolism. Not yet a cure, but AIDS is now officially on the run.
Curing viral disease tends to be more difficult. We have yet to develop any real cure for the common cold, a disease that we naturally recover from in a week or two. Part of the reason for this is that virus's aren't, in most senses of the word, alive. They are naked chunks of protein progammed to replicate endlessly, like some sort of zombie. And like zombies, they tend to keep going until totally destroyed.