David Harrich, from the Queensland Institute of Medical Research, said he had successfully modified a protein in the Human immunodeficiency virus (HIV) that the virus needed to replicate and instead made it "potently" inhibit virus growth.

"I have never seen anything like it. The modified protein works every time," said Harrich.

"If this research continues down its strong path, and bear in mind there are many hurdles to clear, we're looking at a cure for Aids."

Harrich said the modified protein, which he had named Nullbasic, had shown a "remarkable" ability to arrest HIV growth in a lab environment and could have exciting implications both in curbing Aids and treating existing HIV sufferers.

He described it as "fighting fire with fire".

"The virus might infect a cell but it wouldn't spread," said Harrich of his study, published in the latest edition of the journal Human Gene Therapy.

"You would still be infected with HIV, it's not a cure for the virus, but the virus would stay latent, it wouldn't wake up, so it wouldn't develop into Aids," he added.

"With a treatment like this, you would maintain a healthy immune system."

Nullbasic

A person with HIV is said to have Aids when their count of CD4 immune system cells drops below 200 per microlitre of blood or they develop what is known as an Aids-defining illness; any one of 22 opportunistic infections or cancers related to HIV.

The majority of people infected with HIV, if left untreated, may not progress to Aids for 10-15 years or longer, according to the UN. Antiretroviral treatments can prolong this further still.

The new Nullbasic gene therapy, if proven, could see the deterioration from HIV to Aids halted indefinitely, bringing an end to the deadly condition.

Harrich said the fact that a single protein could be so effective could spell an end to onerous multiple drug regimes for HIV patients, meaning better quality of life and lower costs to individuals and governments.

"In that respect, this is a world-first agent that's able to stop HIV with a single agent at multiple steps of the virus lifecycle," Harrich told ABC Radio.

"You either have to eliminate the virus infection or alternatively you have to eliminate the disease process and that's what this could do, potentially for a very long time."

Aids deaths

Animal trials of the protein are due to start this year, with any treatment using it likely to be some years away.

According to the latest UN figures, the number of people infected by HIV worldwide rose to 34-million in 2011 from 33.5-million in 2010.

The vast majority (23.5-million) live in sub-Saharan Africa, with another 4.2-million in South and Southeast Asia.

There were 1.7-million deaths from Aids-related causes worldwide in 2011, 24% fewer than in 2005 and nearly 6% below the 2010 level.

New HIV infections have at least halved in 25 low and middle income countries, many in hard-hit Africa, over the past decade, with particular progress made towards protecting children from the deadly virus.

The UN said in November that achieving zero new infections in children was appearing increasingly possible. – Sapa-AFP