Why are we having such a hard time curing HIV?

I was just curious why some viruses are relatively easy to find a cure or vaccine for, but HIV has alluded scientists for all this time.

So, can anyone, in layman terms ( for this non-biologist :] ), why it is harder to cure or protect against than other viruses?

Their is no lasting cure for HIV because the disease mutates itself very quickly, because as soon as they found a cure for it ... it will just mutate rendering the cure ineffective and useless. When a disease mutates it changes the DNA so it becomes a different type of the same disease, also it damages the body's immune system meaning the body can't fight off the disease.

Its like trying to find a cure for a cold, each time you get a cold its slightly different, thats because the common cold mutates itself very quickly and as soon as a cure is found it becomes immune or mutates itself again and again.

Medicine is not an exact science. Cures for disease tend to work by preparing the body's immune system. HIV attacks the immune system and there's no easy answer. Other drugs work by destroying bacteria (antobiotics) or by attacking viruses (antiviral) but some bacteria and viruses become immune to them. HIV mutates easily and is highly resistant to antiviral drugs. The other method of treating disease is to take away the symptoms so the patient can live a normal life on medication. At present, HIV/AIDS is treated with a cocktail of antiviral and symptom suppressing drugs. HIV is a comparatively new virus and scientific research takes time.

Expanding on Liam's point, say you're an engineer trying to plug a hole in dam. You inspect the dam, and see it has a square hole. You go away to create a square plug, and while you're gone HIV can change the shape of the hole any way it wants, even making it smaller. When you come back to plug the hole, the plug doesn't fit the hole, so you go make another plug and the process repeats. Now imagine it has several million holes, each one representing an infected person, and HIV can move at the speed of light and can drill new holes. Now try plug all the holes. It's an impossible task, unless everything on earth goes extinct.

there have been no cures for any viruses just drugs that help combat the way they replicate.

vaccines are normally weak of dead parts of the virus that allow the body to build up a defense.

HIV mutates too quickly for us to to inoculate against it. this means we could make a vaccine but it will be for a virus that is different by the time it is developed.

also HIV attacks the immune system itself unlike other viruses. you dont die from HIV or AIDS, you die from what ever you get after the virus decimates your system.

Because it requires humans to stop having sexual relations and they won't , So the disease increases , To be safe give up sex altogather ,

The virus mutates very fast.

It's thinning out the drug addicts and the bum bandits so the motivation for a cure isn't there,

Honestly I think they already have a cure but our government is selfish because all of the money they make on medications.