More than three years ago, Australian researchers at St Vincent’s Hospital and the Kirby Institute (University of NSW) transplanted bone marrow to two HIV-positive men. Now the men are apparently HIV free.

Researchers have highlighted the fact that the bone marrow used did not contain both copies of the gene, CCR5delta32, a mutation that protects against the HIV virus, which suggests that bone marrow without this gene could also be used to afford protection against the virus.

The results were presented as part of the 20th International AIDS conference held in Melbourne in July, 2014. The conference was held despite a number of delegates being killed in the Malaysian Airlines tragedy.

Professor David Cooper (UNSW) says that the results herald a new direction in HIV research. He reports that both patients are doing reasonable well years after the treatment for cancers, and remain free of cancer and the virus. Both men, whilst being cleared of the virus, remain on antiretroviral therapy.

Researchers are still working with these patients to discover if there is any residual virus and where it is hiding. Finding where the virus hides is essential to finding a potential cure for HIV.

Until this research, the only person considered to have been cleared of HIV is an American man, who had bone marrow transplants in 2007 and 2008. His donor had both copies of the gene that protects against HIV.

Experts stress that while the Sydney results are significant, bone marrow transplants are not a cure for HIV, as it remains a costly and potentially dangerous procedure.