ARI SHAPIRO, HOST:
Now this week, doctors announced a breakthrough in HIV research. A Mississippi toddler who was born with the virus appears to have been cured. Doctors credit an aggressive regimen of anti-retroviral drugs administered just after the girl was born. This is the second well-documented case of someone being cured. The other involved a middle-aged San Francisco man who received a bone marrow transplant from a donor who was genetically resistant to HIV.