The promising results of a six-month clinical trial of an AIDS vaccine have been called into question, according to two published accounts on Science magazine’s Web site and in The Wall Street Journal.
The reports cited AIDS researchers who received confidential briefings about the trial’s results, and said the effectiveness may be weaker than originally reported last month.
The U.S. Army, the Thai government and the U.S. National Institutes of Health, which helped fund the three-year, $105 million study, announced on September 24 that they had found the first vaccine that provided some protection against HIV, the AIDS-causing immunodeficiency virus.
At the time, the researchers said the combination vaccine had produced a statistically significant 31% reduction in new HIV infections in a trial of more than 18,000 people in Thailand.
While considered moderately effective, it was the first trial to suggest a successful AIDS vaccine might ultimately be possible.
The researchers also said there was only a 4 percent chance the difference was coincidental.
However, an Army scientist involved in the project said a second analysis of the data showed the results weren’t statistically significant, the Journal reported on Saturday.
In other words, the results could have been due to chance and the vaccine may not have been effective.
The additional data were available to the researchers on Sept. 24 when they announced the trial results, but they chose not to disclose them, the Journal quoted U.S. Army scientist Jerome Kim, who worked on the study, as saying.
News of the second analysis was first reported on the Web site of Science magazine, which cited researchers who said the secondary analysis suggested that the vaccine reduced infections by only 24%, rather than 31 % as originally reported.
Such secondary analyses are common for vaccine trials.
The first analysis included all 16,000 trial participants, while the secondary analysis excluded those who did not follow the experimental regimen. When that was done, the results were less compelling.
Dr. Anthony Fauci, director of one of the National Institutes of Health, acknowledged that second analyses of the data could show a weaker effect, but said the original results, which included every trial participant, were “the gold standard.”
Putting several biostatistical analyses in a news release “would have confused everybody,” Dr. Fauci told the New York Times, calling the idea that researchers were engaging in a cover-up “absurd.”
“They couldn’t be that stupid,” he said.
“They were already planning to give confidential briefings to experts. They were about to publish everything in a journal. And they were heading to Paris in three weeks to present the results to the world.”
Comprehensive details of the trial will be made available during an AIDS meeting in Paris that gets underway October 19.
Dr. Fauci said he had not been consulted on how to release the original results, but was asked to take part in a news briefing in Washington the following day because he had overseen the financing and was skilled in articulating complex science.
In hindsight, the Army’s decision to brief other players in the field before the late October Paris conference “backfired”, he said.
Some 33 million people were living with HIV in 2007, with about two million having died from AIDS that year, according to the latest data from the United Nations.
There have been more than 100 HIV vaccine trials since 1987, none of which were successful until the Thai trial.
—
On the Net:
Comments