The federal government Friday reluctantly dropped charges of scientific misconduct against Dr. Robert C. Gallo, the pioneering researcher who has spent the past decade fighting accusations that his role in the discovery of the AIDS virus was tainted by failure to give proper credit to French scientists.
The decision by the Office of Research Integrity reversed an earlier guilty finding. It came just three days before a hearing was to begin on Gallo's appeal and brought an official end to what may be the most closely watched ethics probe in modern medical science.
It did not lay to rest the international controversy over who discovered the AIDS virus. In the wake of the ruling, French scientists once again demanded full credit for the discovery and all royalties from the blood test it made possible--despite a 1987 accord in which France and the United States agreed to share credit and split the money.
Gallo was cleared last year of the most serious allegation, a charge that he stole the virus from the Pasteur Institute in Paris. But, in a serious blot on his career, he was found guilty of scientific misconduct for failing to acknowledge the contribution of French scientists to his work.
Government investigators made clear Friday that they are still troubled by his actions in the early to mid-1980s, saying they withdrew the charges solely as "a practical matter." A recent legal decision, they said, set "a new and extremely difficult standard" for proving scientific misconduct.
"Clearly, we weren't happy to do it," said Dr. Lyle W. Bivens, who heads the Office of Research Integrity. "We felt that we couldn't proceed with our case."
But the 56-year-old researcher, who has vehemently denied wrongdoing, declared that he was "delighted" by the ruling.
"I have been completely vindicated," Gallo said in a brief statement. "I will now be able to redouble my efforts in the fight against AIDS and cancer."
Widely regarded as a brilliant scientist, Gallo is known as much for his brusque manner as for his contributions to AIDS and cancer research. His lab at the National Cancer Institute is working on an AIDS vaccine, and on gene therapy treatments for AIDS and cancer. He has also helped develop drugs that are being tested for Kaposi's sarcoma, a cancer common to AIDS patients.
Friday's decision was not entirely a surprise. Last week, in a related case, an appeals panel overturned a judgment against Dr. Mikulas Popovic, who had carried out crucial AIDS experiments under Gallo's direction.
Like Gallo, Popovic was found guilty of scientific misconduct last year by the Office of Research Integrity, an arm of the U.S. Department of Health and Human Services. When Popovic won his appeal, it became apparent that Gallo--whose hearing was set to begin Monday morning--would win as well.
In the Popovic decision, the appeals board ruled that false statements alone were not enough to warrant a finding of scientific misconduct. Rather, the board said, the agency would have to prove that the statements were deliberately deceptive, that they had a significant effect on the research conclusions of the paper and that there was no possibility of honest error.
Bivens said it made no sense to go forward under those terms, "in the face of virtual certainty that we would lose." He added that his office intends to work toward legislation that would make such cases easier to prove.
Controversy has swirled around Gallo's research since 1984, when he published a paper in the prestigious journal Science that described how he had discovered the virus that causes AIDS. At the time, researchers worldwide were racing to find the cause of the mysterious new disease.
One year earlier, researchers in the laboratory of Dr. Luc Montagnier at the Pasteur Institute in Paris had published similar findings, saying they had isolated a virus taken from AIDS patients, but were uncertain whether it caused the disease. Calling the virus LAV, they sent two samples to Gallo's lab.
When Gallo's paper appeared in Science, critics accused him of stealing the virus from the French and taking credit for their work. Although Gallo denied the claims, later analysis showed that the virus he had isolated was nearly identical to that of the French, indicating that it may have been the same virus.
In 1985, when the AIDS blood test was licensed, the French sued the U.S. government over credit for the discovery of the virus. That suit was settled in 1987 with an agreement signed by President Ronald Reagan and French Prime Minister Jacques Chirac naming Gallo and Montagnier as co-discoverers.
France is now trying to renegotiate that agreement. In a statement Friday, lawyers for the Pasteur Institute said the U.S. government is "obligated by both conscience and its commitment to scientific integrity" to give them full credit.
Although the matter was the subject of international negotiations, the U.S. government did not launch a formal ethics probe until 1989, after the Chicago Tribune published an extensive article detailing the charges against Gallo.
The government took three years to investigate. Last December, the Office of Research Integrity cleared Gallo of the charge that he stole the virus from the French, but concluded that he had "falsely reported" the role that the French samples had played in his work in an intentional effort to mislead colleagues and gain credit for himself.
The agency also found that Gallo had failed to give proper credit to American scientists who developed the cell culture in which his researchers grew the AIDS virus. The report also charged that Gallo withheld the AIDS culture from other laboratories, slowing the pace of research.
Gallo appealed. "The charges against Gallo were false," said his lawyer, Joseph Onek, on Friday. "They were always false. The government, despite all this rigmarole, withdrew the case because it knew it could not prove these false charges."
Times staff writer Robert L. Jackson in Washington contributed to this story.