Consternation over HIV vaccine trial failure

Volunteers who participated in a failed vaccine trial will now be told whether they received a vaccine that could make them more susceptible to the AIDS virus.

Last week, researchers involved in the international trial of the HIV vaccine revealed not only that it did not work, but that those who received it were more likely to acquire HIV.

Three thousand people around the world took part in the study, including 19 people in Sydney.

While the vaccine has now been ditched, research into why it failed will continue for years to come.

V-520 was the first AIDS vaccine to be trialed on humans. Researchers had great hopes for it because it worked so well in laboratory trials.

Associate Professor Tony Kelleher is the head of the immuno-virology and pathogenesis program at the National Centre in HIV Epidemiology and Clinical Research at the University of New South Wales.

He is also principal investigator for the vaccine trial in Australia.

"There's been a formal decision to un-blind all the participants," he said.

"So the trial was a double-blind trial, where neither the people administering the vaccine or the people receiving the vaccine knew whether they were getting the vaccine or the placebo.

"There has been a process, since the results of the trial were known, where individuals on request, if they were distressed by it, the news about the results of the trial, could request to be un-blinded and that had been happening in the background, and so they were told whether they got vaccines or placebos."

Of the 3,000 people enrolled in the trial, half of them were given the vaccine.

The trial was stopped in September, when researchers released the vaccine was not working. Last week, they revealed the devastating news.

Associate Professor Kelleher says somehow those who were injected with the vaccine were more susceptible to infection with the AIDS virus.

"We contacted all of them last week prior to the news of last week breaking in the press and told them what where the results were," he said.

"At that stage about half of those individuals requested to be un-blinded, and that occurred last week.

"Since then [there's been] another couple of requests to be un-blinded, so there's still about eight people in the trial that are still blinded at the moment."

Associate Professor Kelleher says the information has clarified things for the participants.

"I think knowing whether they got the vaccine or not has helped them understand the implications of the trial for them," he said.

"I think it's helped them come to terms with the results in an individual fashion rather than it being something that's occurring in a group of individuals."

None of the Australians has developed HIV.

Last week, researchers said they did not know whether to reveal just who had received the vaccine because they feared the volunteers would change their behaviour, tainting research results.