MELBOURNE University researchers have identified antibodies that fight HIV in a breakthrough that brings closer the ''holy grail'' of developing an effective vaccine against the virus.
A study of 100 people with HIV, recruited from The Alfred hospital and the Melbourne Sexual Health Centre, showed the antibodies were so successful in suppressing the virus that it had to mutate around them.
The discovery has raised hope that the antibodies, if introduced to healthy people, could prevent the virus taking hold.
The study has been published in the journal Proceedings of the National Academy of Sciences.
Senior author Stephen Kent, of Melbourne University's department of microbiology and immunology, said developing a vaccine was ''the holy grail'' of research into HIV, which has infected 30 million people worldwide.
''In Australia we treat people with drugs that restore the immune system, but unfortunately that's not an option in many parts of the world [due to cost] so it's important that we prevent this infection,'' Professor Kent said.
''We've been working on this problem for over 10 years and the vaccines we've tried in the past have induced some immune responses but they have not been very effective.
''We think we know why now; we think we were inducing the wrong immune responses. If we can use this knowledge to induce the right immune responses, we hope to really knock this on the head.''
Professor Kent said his team studied blood samples of HIV-positive people and analysed how the antibodies (called antibody-dependent cellular cytotoxicity) targeted the virus.
''We were very surprised to see the virus was mutating around these antibodies,'' he said. ''As a result, the antibody isn't entirely successful in getting rid of the virus in people with HIV.
''But if you were to have those antibodies before you caught the virus and it started replicating - giving the immune system a head start - we think it would prevent the virus taking hold at all.''