Two a penny

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Scientists have identified two powerful antibodies that point to a new target for an Aids vaccine, by probing the blood of a rare group of people who contract HIV but develop resistance. .

They are the first to be identified in more than a decade, and the first to be identified in an HIV-infected but otherwise resistant person from a developing country.

“I think this is a very significant finding,” says Prof Purcell, who heads the Molecular Virology Laboratory at the University of Melbourne.

Commenting on the research, Melbourne-based Associate Professor Damian Purcell said the discovery had pointed to a new and potentially broadly available “chink” in the Aids virus’ armour.”

Work towards an HIV vaccine has continued for decades, and its success hinges on finding an unchanging part of the virus which otherwise mutates furiously inside the body.

“And it’s actually a foretaste for what we’re going to require over the next couple of years in order to make an effective HIV vaccine.

The search is centred on a rare group of people referred to as “elite neutralisers”, because while they had contracted HIV they appeared to live without ill effect.

They settled on a sample from an HIV-resistant Kenyan man, and the unique antibodies found in his blood were shown to work against a part of the virus not considered for potential vaccine application before.

The IAVA research, published in the journal Science, took in 1,800 blood samples from HIV-infected people across the African continent but also from Australia, Thailand, the UK and USA.

“They chose an elite neutralising patient in Africa, and the antibodies they plucked out were able to neutralise viruses from Australia, from USA, from Asia,” Prof Purcell says.

It also worked against a range of different HIV strains, Prof Purcell says, raising hopes of finding “the chink in the armour, the susceptible target that seems to be across all of these (HIV) viruses”.

Prof Purcell also says the effort to develop an HIV vaccine could continue for another five to 10 years but “at least we now know what we’re aiming at, the target has become more visible”.

It was also “very potent” compared to earlier antibody discoveries.

Further developments in HIV will be discussed at the 2009 Australasian Sexual Health Conference, to be held back-to-back with The Australasian HIV/Aids Conference 2009, in Brisbane next week.

Further developments in HIV will be discussed at the 2009 Australasian Sexual Health Conference, to be held back-to-back with The Australasian HIV/Aids Conference 2009, in Brisbane next week