Because they don't get sick, elite controllers hide in plain sight – even from themselves – however, a team of Victorian researchers and doctors has tracked down 22 of these people in Melbourne and Sydney.

They have been closely studied for the past three years by a group headed by the Doherty Institute's Professor Stephen Kent, an immunologist and infectious diseases expert.

"People that find out that they're HIV-positive hope they're one of these people but only one in 1000 with HIV is actually that person. They think they've won the lottery," Professor Kent said.

The team, which includes infectious disease physician Dr Ivan Stratov, has discovered elite controllers produce a lot of something that others don't. It's called antibody-dependent cellular cytotoxicity (ADCC) antibodies and they believe it could be the missing link to a vaccine, and may even help pave the way to a cure.

"Elite controllers produce a special type of antibody that is able to kill HIV very effectively," Professor Kent said. "They're not cured but they're controlling it without drugs, which is the next best thing."

HIV drugs, which have been saving lives for years but have side-effects, must be taken for life and are expensive. It costs the government about $14,000 a year for drugs to cover just one of an estimated 27,000 people with HIV in Australia, Professor Kent said.

The research is set to be published next year and has "bolstered evidence that ADCC will be important for a HIV vaccine," he said. "It's still a long way off but it's a bit of an 'aha' or eureka moment for us."

Professor Sharon Lewin, a global expert on HIV, said ADCC was probably an important part of how elite controllers were controlling the virus, but one of several others.

"It's not going to be one particular part of the immune system, probably a few different parts of the immune system, that together give you good control," she said.

Now researchers have identified the antibody they're trying to find a way to isolate it and test it as a vaccine prototype.

Through their work with the ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, the researchers are also modifying nanoparticles to work out how to target cells for a possible vaccine.

The research into controllers goes back to the 1980s and a Victorian man who watched two of his partners and many friends fall to HIV, while he inexplicably remained healthy.

Greg Brown was 26 when he and his first partner were diagnosed in 1984. It was before HIV drugs, and they were told they would both be dead within four years.  His partner died in 1993 but Mr Brown lived and went on to lose a second partner, Trevor, more than 10 years later.

Mr Brown had accompanied Trevor to a medical appointment at a sexual health clinic in 2004 and that's when he met Dr Stratov and asked the question nobody had seemed able to answer: why wasn't he sick?

"If I could have swapped places with either of my partners in that bed I would have," he said.

"I feel blessed and privileged to be able to work with Ivan in the hope of ending the pain and suffering caused by the HIV virus on a global scale."

Dr Stratov said  Mr Brown became the inspiration for the elite controller research, and although he is a controller, his body does not control the virus to the same level as an elite.

In Mr Brown's blood researchers had found the ADCC antibodies were targeting a part of HIV that had not previously been thought important for a vaccine, Dr Stratov said.

"ADCC targets the cells in which the virus is living and if you can kill the cells, well then you disable the virus," he said.