When they are used the right way, every time, they can help protect against HIV and other STDs. I heard a cure was announced in South Africa. We receive many cures through the mail as well. There are people who investigate those claims, and if they are being used on someone, it can be. That is what kills someone.
Most people develop detectable antibodies within three months if they are really infected.
It is better to remain not at risk. There are concerns about resistance because people don't take it properly or off and on, etc. NIH performs research. There are also independent organizations and drug companies who do research as well. There are different levels of research, so I couldn't say where most of it is being done.