Typically HIV-positive indivuals take anti-retroviral drugs to treat the virus. But a 42-year-old American man living in Berlin was HIV-positive until a bone marrow transplant with cells from a donor naturally immune to all forms of HIV. Doctors have not detected the virus in his blood for over 600 days.
The cells are immune to HIV because of a genetic mutation, which 1% of Europeans but almost no Africans or Asians carry. In the Berlin case, doctors killed all of the patients own bone marrow cells and then injected the new cells from a donor with both parents bearing the specific genetic mutation. During this entire process, the patient was not taking his typical dose of medication.
But does this mean you can fling off your condoms? Does this mean you should not get tested once a year, or more? No, of course not. But we're anxious to see this potentially life-saving treatment tested again and again. If it really works, millions of lives can be saved.