More than half a million people in the U.S. have died from HIV infection, and more than a million currently live with the virus, but a relative handful of people infected with HIV never get treatment for it and never get sick from it. The immune systems of this small population—perhaps 50,000 Americans—somehow control the virus for long periods of time. Of course, there is typically a bell curve of response to any disease, but figuring out how these people control the virus is one of the most vexing mysteries of the AIDS pandemic. Solving it might unlock new ways to prevent and treat HIV infection, and now several research teams are going after the answer.
Ten years after infection with HIV, a typical person has progressed to where tens if not hundreds of thousands of copies of the virus can be found in a single milliliter of their blood and more than three quarters of their CD4 immune cells are destroyed, if they have not started drug therapy.