From the printed edition of The Economist, March 19, 2013
In journalism, cynics suggest, three data points are enough for a trend. As of March 4th, AIDS researchers hope two might be sufficient. On that day Deborah Persaud of Johns Hopkins University announced to the Conference on Retroviruses and Opportunistic Infections, in Atlanta, Georgia, that a patient under her care had been cured of HIV infection. The announcement was hedged with caveats (“functionally cured” was the exact term used). But the bottom line was clear. Dr Persaud thinks her patient, a two-and-a-half-year-old girl, has joined Timothy Brown, a man known to many as the “Berlin patient”, as a human who was once infected with HIV and now no longer is.
The girl was born infected because her mother was infected but was not under treatment at the time (which would normally prevent mother-to-child transmission). She was given standard anti-retroviral drugs almost immediately and for 18 months afterwards. Doctors then lost track of her for five months and when she returned to their attention, they found the virus had vanished. Half a year later, despite the fact that she is no longer taking anti-AIDS medicine, there is no sign of HIV having returned.
This is a result of great potential significance. Mr Brown’s cure was effected because his bone marrow (and thus the pertinent part of his immune system, which HIV infects) was destroyed and replaced during a course of treatment for leukaemia. That is hardly a viable approach for most people. But if HIV infection can be cured with drugs, as Dr Persaud’s observations suggest, a whole new line of investigation opens up.