When doctors eradicated HIV in an American man in Berlin, news outlets declared, “A cure for HIV!” But does a cure for one man mean there’s now a remedy for all? Not quite.

The man, Timothy Ray Brown, had recurrent leukemia in 2007. Treatment for this type of cancer involves wiping out the patient’s entire immune system with chemotherapy and then supplying a new system through a bone marrow (a.k.a. stem cell) transplant. So Brown’s docs at the University Medicine Berlin cleverly found a donor who had a particular genetic quirk that makes the body resist HIV. The result? In December 2010, Brown’s medical team said evidence “strongly suggests” he has been cured of the virus.

Nobel Prize–winner David Baltimore, PhD, who researches genetic therapies for HIV at the California Institute of Technology, said that unfortunately this case is “very difficult to duplicate—virtually impossible on a large scale,” because such transplants are very dangerous and expensive and the chance of finding the proper bone marrow donor so rare.

But, Baltimore says, the news that HIV can be cured is “extremely encouraging.
I see many people trying very hard to develop safe and effective genetic therapies for HIV that can be used on a wide scale.”

With Brown’s cure as a starting point, we just might get there.

For more information on Timothy Ray Brown, click here.