A 60-Year-Old Man in Germany is at least the seventh person with HIV, who was announced as virus-free after he has received a stem cell transplantation 1 . However, the man who has been virus -free for almost six years is only the second person who has received stem cells who are not resistant to the virus.

"It is very surprising that it worked," says Ravindra Guppa, a microbiologist at the University of Cambridge who led a team who has dealt with one of the other people who are now HIV-free 2 , 3 . "It's a big deal."

The first person found after a bone marrow transplant to treat blood cancer HIV-free 4 Some other received special donor stem cells 2 , 3 . These wore a mutation in the gene that encodes a receptor called CCR5, which is used by most HIV virus trees to penetrate in immune cells. For many scientists, these cases indicated that CCR5 the best goal for a HIV healing

The latest case-presented at the 25th International Aids Conference in Munich, Germany, this week-turns this upside down. The patient, called the next Berlin patient, received stem cells from a donor who only had a copy of the mutated gene, which means that their cells express CCR5, but in a smaller amount than usual.

The case sends a clear message that the search for a cure against HIV is not only about CCR5, says the infectious disease doctor Sharon Lewin, who is leading the Peter Doherty Institute for Infection and Immunity in Melbourne, Australia,.

Ultimately, the results expand the donor pool for stem cell transplants, a risky process that is offered by people with leukemia, but probably not introduced for most people with HIV. About 1% of people of European descent wear mutations in both copies of the ccr5 -Gens, but about 10% of people with such ancestry have a mutated copy