WHAT'S GOING ON?" HE ASKS. "Please, tell me why they do this to me."

There are those out there who despise Dr. Robert Gallo. He discovered the cause of AIDS and is now at work on a vaccine, and yet he needs only to open his mail or make a trip, and there they are, the bizarre accusations, the flashes of hatred. Recently, critics in the Eastern Bloc accused him of creating the AIDS virus in his lab in Bethesda as a weapon of chemical warfare. A few months ago in Wiesbaden, he had to walk past a phalanx of West German acolytes of Lyndon LaRouche who were passing out leaflets denouncing him. He has had to stand before a huge audience at Cambridge University and listen as a British scientist in the audience, Alexander Karpas, accused him of stealing key AIDS data from a lab in Paris.

And one day last year, the best known AIDS sleuth in the world opened his mail and found a copy of New York Native, a gay newspaper published in New York. The Native had already attacked him as a thief, a fraud, a homophobe and a schizophrenic, so Gallo was right to wonder just how far the editors would go this time. They did not disappoint him. On the cover was a doctored picture of Gallo dressed in the bangles and plumes of Carmen Miranda. A photo of his face had been pasted over Miranda's. The headline read "Science's Greatest Living Performer."

"I can't tell you how much the criticism hurts," he says now before embarking from Dulles on a European lecture tour. "Even the outlandish, absurd stuff from people who don't know the least thing about science. My colleagues say I should let it pass and concentrate on science. But it hurts. Why should I tell you any different? It wounds. The people that know -- they understand I'm doing everything I can. And we've had amazing success. But then the other stuff. I'm telling you, there are days when I wake up in the morning and feel like the archangel Gabriel. By the time I go to bed at night, I feel like Lucifer."

A reasonable response, but then, as is his habit, Gallo lets loose with the sort of screed his admirers would prevent if they only could. He cannot help himself. Of some of his "fringe" gay critics, he says, "People like that, who already feel that society is oppressing them and they've lost their best friends and they themselves may have virus on the brain, it's not unreasonable for them to have fears.

"A leading German homosexual said I had millions of dollars in my pocket. It's absurd, but I could get assassinated for something like that! What drives these people? Insanity. Severe paranoiac jealousies. The desire to get famous. People tell me 'don't respond,' but sometimes I just have to."

More respected critics -- indeed, some of his colleagues -- have faulted Gallo for his behavior during a two-year-long dispute with French research scientist Luc Montagnier over who could claim credit for identifying the AIDS virus. Although both men extended the dispute far beyond the point of their colleagues' patience, Montagnier publicly affected a Gallic hauteur even while he was filing lawsuits and playing scientific politics with all the skill of a Chicago alderman.

Gallo, on the other hand, has no genius at all for public relations. He made his case with acid public remarks that fairly burned through the newsprint they were printed on. In a field that tries to hide its competitiveness behind a curtain of altruism, Gallo stands center stage, naked, speaking his piece. He cares deeply about AIDS, but he does little to hide his ambitions, his hurts, his envy, his disdain. He says what he is thinking at the moment. "I can't always help myself," he says.

Says Dani Bolognesi, an AIDS researcher at Duke University, "Bob's major trouble is how he comes across. We'd all like to see him as a leader -- calm and direct, not as emotional and turbulent as he is. But the man is Italian. If he were in private industry, there would be a public relations department wrapped around him. But he's just out there by himself, being himself."

The days are gone when Gallo spent long days in the glass menagerie of the lab. Now, as chief of laboratory tumor cell biology at the National Cancer Institute, he is mostly the intellectual and administrative Ubermensch, a force that proposes while his team disposes. He spends nearly a third of his time traveling as a high-flown medicine man, exchanging ideas, information and not a little gossip at institutes and hospitals across Europe. He is a bookish figure, with an intense stare, a hawk nose, graying hair. For a sedentary man of 50, he is trim. Though he eats like a horse, he has the metabolism of a hummingbird. "You might say that Bob is always moving," says his wife Mary Jane. "Even when he thinks, he moves."

For years, Gallo made dramatic advances in cancer research at the National Institutes of Health -- among them the discovery of interleuken-2, a substance crucial to leukemia treatments, and the discovery of the first human retrovirus, identifying a category of viruses that includes certain leukemias and AIDS. Without his knowledge of human retroviruses, present AIDS research might well be years behind where it is. Even before he turned his attention completely to AIDS, many of is colleagues wondered why he had never won a Nobel Prize. NIH's Samuel Broder, a cancer expert, says, "Gallo is one of the paradigmatic figures of the 20th century. He's influenced things in our daily lives to an incalculable degree. Einstein, Freud -- I'd put him on a list like that, I really would." Gallo's fame before AIDS was of the most soothing, secure sort: the admiration of his peers.

AIDS changed all that. When the disease was first identified six years ago, many scientists decided to keep their distance and work on other things. Those that stayed clear of the AIDS labs were not only the lab technicians who feared infection, and the clinicians who could not handle the death toll, but also immunologists and molecular biologists who sensed the pressure of public despair.

For AIDS is like nothing else any scientist has ever confronted. To think of it as a plague is almost a comfort. Plagues that swept through the towns of Europe and Asia vanished as mysteriously as they had appeared. AIDS shows no sign of disappearing on its own. Even the most radical restructuring of our social and sexual lives will do little more than ease its spread. Nature will not stop AIDS. Doctors will. And the men and women who are now at work on medications and vaccines in places like Durham and Paris, Kinshasha and Bethesda know a kind of tension unsurpassed in the annals of medicine.

"I know there are a lot of people out there who think we're moving too slow," Gallo says, boarding the plane, "but the truth is, I don't think there's ever been quicker progress on a problem this difficult.

"As bad as things are, as bad as they might get, we're lucky, in a way, that AIDS came when it did. If AIDS had shown up in the early '60s instead of the early '80s, we'd be at a loss. We wouldn't have known what to make of it. We wouldn't have had the technology to grow the virus in the lab so that we could work on it. We wouldn't have known anything about retroviruses, the complex, elusive virus that AIDS is. God knows how many people would have died. And we would have been almost paralyzed. It's incomprehensible."

There are hundreds of scientists now at work on a vaccine, but Gallo is one of the few who could make the great leaps of imagination necessary to find it. Most scientific minds are keen and exacting, prizing exquisite, incremental gain. Such scientists are like modern Handels spinning faultless, developing fugues. "Bob Gallo has a different style," says Dr. Max Essex, a prominent AIDS specialist at Harvard. "He has had more major discoveries than anyone I know of, and they come from taking big chances. Relatively few scientists like to take chances. Only a few can, and Gallo is the extreme in that direction." Gallo himself says, "I'm more a Beethoven type," a romantic, full of symphonic flight, voices and cacophony.

Bolognesi says, "A lot of the aggressiveness that people don't like about Gallo is part of why he's accomplished so much." "That's true," Essex says. "Other scientists get resentful. They're jealous of someone who thinks like that, and sometimes they strike out at him."

Gallo knows he should ignore the catcalls. Especially from the cheap seats. Instead he keeps his ear cocked. ("My God, they keep portraying the Montagnier thing like it's the poor little Frenchman versus the big bad American!" "My God, they're lunatics!" "My God.")

He is incapable of turning away.

"Why do they say these terrible things about me? Do you know? Do you?" AS HE STARES INTO HIS COMPLIMEN- tary glass of Campari, Gallo sees a ghost.

". . . Her face was white and her mouth was filled with blood . . ."

He remembers the nightmare moment of his life, the day 40 years ago that both devastated him and revealed to him his mission. For weeks his parents had left him with relatives near home in Waterbury, Conn., while they stayed near his 6-year-old sister Judith, who was wasting away from leukemia in hospitals in Hartford and Boston. The Gallos were gambling, letting the doctors use chemotherapy drugs on their daughter long before it became a common practice in cancer treatment. Eventually, they let Robert visit Judith in the hospital.

"Until I saw her that day, I thought they were just pampering her. I didn't understand. I couldn't believe what I saw." Judith was jaundiced, dazed. "Like a concentration camp victim." And as she opened her arms to embrace him, Robert trembled with fear, thinking, "She looks like a ghost."

"When I saw her that day, there was a chance she was going to make it. At least for a while. But then she relapsed," Gallo says. "She came home in a casket maybe 10 days later. It was horrible. My first exposure to death. My mother was sad enough, God knows, but my father cracked up totally. We had no more Christmas, no more Thanksgiving, no more Easter. For years we couldn't play music in the house. He had a metallurgy company and he started going back to work, but he went to the cemetery twice a day for years. He went around the house kissing her picture and holding the picture to his heart.

"He was filled with guilt. I suppose he regretted not spending enough time with her. Deep down, he must have felt my sister's death was punishment for his anti-clerical behavior. He'd never been religious before, but then he started going to church every day and giving money for the mass.

"He started spoiling me thoroughly, and gave me everything I wanted. More than what I wanted. I wanted him to stop giving me things, to leave me alone. He was always there to pick me up at school or at ball games. I wished that for once somebody else's parent would be there. But it was always him."

The plane taxis down the runway, making an awful screaming sound. The flight attendant begins her slow ballet of safety instructions.

". . . Death is horror. Just horror. After a while, I felt angry. One day I started to scream in the house. Four years had gone by already. It was the anniversary of my sister's death and I just started to scream, 'Aren't we ever going to be normal again? When will we be normal?' "

It took a long time. Gallo's mother, Louise, worried for years that her husband would "die of grief." But Francis Gallo lived to see his son become one of the country's leading specialists in leukemia and, later, the head of NIH's AIDS team. When Francis Gallo died a few years ago, Louise found in his library dozens of clippings describing his son's accomplishments. "Maybe something good came of our tragedy. Robert decided to become a doctor," she says. "He wanted to find out what killed his sister."

Aloft now, balancing a fat sheaf of scientific papers on his knees, Gallo considers what might have become of him. Until his sister's death, he had been an indifferent student, happier in poolrooms and schoolyards than classrooms. Mary Jane Gallo knew her husband when they were both in their early teens, and she remembers him as "a sad young man." Around that time,ntroduced him to the pathologist who made the original diagnosis of Judith's cancer. Gallo was astonished by Marcus Cox, not only for his scientific mind, but for his temperament. "I'd never met anybody like that. Cynical. Critical. It was the first time I met anyone like that -- taunting all the other doctors. I began spending my summers at his office instead of playing basketball."

Gallo began reading widely in chemistry and the history of medicine. He started with books like Paul De Kruif's Microbe Hunters, a hyperbolic history of Pasteur and the other pioneers of microbiology. It is full of purple prose and bravery -- ". . . this is the tale of the bold and persistent and curious explorers and fighters of death . . ." -- just the sort of thing to fire and guide a young imagination. Soon Gallo was immersed in the rudiments of chemistry, valences and specific gravities, the inert gases and Avogadro's law. Study focused his grief, made use of it.

"For years, you know, Bob refused to make the connection between the death of his sister and his career," says Mary Jane Gallo. "He'd built a very high denial system. He didn't want to appear to exploit her somehow, or to be histrionic. But there is a strong connection, and he feels it deeply."

Gallo turns now to a stack of papers that amounts to a report on the state of our modern plague. There are requests for lectures, horrific statistics, pleas for help.

There are few people more important to the immediate future of the public health. And a ghost brought him here.

"It's so strange how certain people get to where they are," he says. "Right now, I'm in a race. It's strange." AS THE PLANE HITS THE GROUND IN West Germany, Gallo tries to adjust his watch. Frankfurt is six hours ahead of Washington. A summa cum laude graduate of Providence College, star of his class at Thomas Jefferson Medical College in Philadelphia, possessor of honorary degrees at universities from Turin, Italy, to Rochester, N.Y., to Tel Aviv, Gallo is at a dead-end loss. A $20 watch defeats him.

"Damn this thing," he says.

Pushing button after button, he has succeeded in sending the thing into a berserk frenzy of useless flashing. He has viewed and reviewed the calendar. He has cursed the day he bought it.

"Oh, the hell with it," he says. "You try."

Gallo is in West Germany partly to meet with colleagues, partly to pick up a lecture fee. By staying at NIH instead of working for Repligen, Biogen or any of the myriad other private biotechnology companies that are now relieving the academy of much of its best talent, Gallo makes a government salary of about $60,000. A few months' wages for a Rockville tummy-tuck specialist. He lives with his wife and two sons in a house in Bethesda his father bought for him long ago, and he expects to inherit a "decent amount" of money one day. He has financial struggles both profound and banal -- a $30,000 hospital bill for a member of his family, a "gigantic crack in the swimming pool," a new deck. He is relentlessly prideful about his relatively modest means. "I don't even have a car!" he says. "I rely on other people for a ride. They say I'm flamboyant. You call that flamboyant?" If he does leave NIH -- and he may yet move to new labs at Duke -- it will be more for better facilities than for salary.

His asceticism, however, knows limits. When he travels, Gallo likes to be babied. Flights are always business- or first-class. A trip in coach is "hell." He is, by now, fairly expert on the amenities of various countries and tends o view nations on the basis of how well he is coddled. England is "quaint, with lousy bathrooms." Japan "is a dreamland. There's always someone there to pick me up." India was "amazing. I went there for an award and they treated me like a maharajah. They put garlands of flowers around my neck and sprinkled me with oil. What a place." At the Frankfurt airport, he gets whiny and skittish when his ride to the Paul Ehrlich Institute fails to show.

"Nice service," he grumbles. "What am I supposed to do?"

A cab is suggested, and he accepts this intricacy. At the institute, Reinhard Kurth (beard, suit, accentless English) greets Gallo, and with no more than a half-minute of pleasantries ("Oh, fine, and the wife?"), they are deep into a discussion of the virus. There is passion in the talk. Behind the thicket of abbreviations, there are overtones of awe, even admiration for the enemy, for AIDS. One colleague has suggested that while most viruses are as simple as a "cowboy's coffeepot," the AIDS virus is as ornate as an "Italian espresso machine." "This virus is so fascinating that sometimes I have to step back and remember what the hell it brings," Gallo says.

Kurth invites several of his researchers to meet with Gallo. It is a nerve-racking experience for them as they sit around a table and offer their latest findings. Gallo is rarely capable of hiding his emotions. When he finds a presentation dull, his face slumps and he begins to nod, as if to urge the fellow to hurry up and get it over with already. Sometimes his remarks cut -- "Is that what you really think? Really?" -- and yet he seems to have little idea of how severe his words can be. When he is engaged, it is easy to see his mind race. He begins to pump his knee under the table, narrow his eyes and shoot out encouraging remarks. "Yes, oh yes, you must do more with that!" When the idea takes a false turn, his disappointment often takes shape as a sneer. Even at home, Mary Jane Gallo says, "Bob has to make an extra effort to listen carefully to what other people say, even if he thinks they're wrong. He's had to learn to listen more carefully to me and our {two} boys. He can overwhelm people. But he's working on that."

The subject turns to Africa, where AIDS is most prevalent and probably began. Gallo and nearly all others in the field believe the virus began around the rural areas near Lake Victoria. The virus probably passed from African green monkeys into man when hunters ate the animals or, less likely, when monkeys bit their human predators. "Who really knows?" Gallo says blithely. "Maybe there's some ritual with monkey blood -- who knows? They do a lot of funny things in Africa, like when they make the lower lip stick out or when they put things through their noses." According to Gallo, Belgian missionaries reported illnesses resembling AIDS as many as 25 years ago, but those reports soon passed. Tribes were more isolated from one another then, and such a disease was unlikely to go far. The virus began its spread with the change in African demographics and sexual habits.

"Tribes began to be less isolated," Gallo says. "There was more social and sexual contact between tribes, and people began moving more into the cities. There's been a rise of prostitution and promiscuity. The infection rate in places like Zaire and Kenya is astronomical.

"The ancient Romans had a saying: 'Anything new . . . Africa.' "

Later, as the statistics and tone of discussion reach a climax of grimness, Kurth pierces it.

"You know, Bob, we all better stay with our wives," he says. "Everything else is too dangerous." Gallo smiles. The young, unmarried researchers do not. ALLO RARELY SEES A SICK PERSON.

Once or twice a year, not more, he will make the rounds of AIDS patients at one hospital or another. He will only go if invited, and then, reluctantly. The visits always move him. "But the truth is, I'd really rather not go," he says. "I have nothing to offer them. It's a useful reminder, sometimes, but I don't think it helps me solve the problem. It just gets me more emotional. I've got to keep my eyes on the best scientific approach. I don't want to be in a position where I'm so emotional that I'd just run out and grab onto just anything."

When he is not abroad, Gallo presides over the AIDS lab at NIH's Building 37, a world that grows ever more remote with time from the clinic. As his medical science progresses, the focus gets smaller and more complex. In the paintings of Thomas Eakins, medical minds would gather around a corpse and rummage through its bones, its guts. They would find what they would, and doctors would apply this knowledge, healing as best they could. Now, the components of research are not guts, but fractions thereof: cells, viruses, genes, antibodies, enzymes.

In college, Gallo understood that "the crude animal physiology was over. Medicine was moving more and more into biochemistry." A fortunate thing for him. In an attempt to understand how the thymus gland worked, he tried a decidedly crude experiment. To examine the organ, it had to be removed. "So I sent my mother a lot of lab mice to keep in the garage. For about six weeks she fed them and watered them, until I came home. It was a disaster. I never learned how to operate

continued on page 39 properly on the mice, and I'd kill 'em. No mouse survived me. You know, you can cut the chest and get the thymus out, but I was probably cutting the heart, cutting the aorta, or maybe they died of shock. I learned a lot about my mother from it. There were a lot of mouse babies after a while, and she got fed up."

At Jefferson Medical College, Gallo worked on dogs. In order to study a hormone that causes the growth of blood cells, he "and another crazy med student" tried to use a heart-and-lung machine for their experiments. Alas, "no dogs survived. There was blood all over the place. We killed three dogs and couldn't get any experiment to work. Sooner or later, I learned that cells are a lot easier to work with. They don't bite or bark, and they don't mess on you, either."

Gallo soon found a mentor in microbiology, Dr. Alan Erslev, and began sneaking out of clinics on orthopedics, dermatology and neurology to get back to Erslev's lab. Patients, with all their human qualities, have just never held the same fascination for him as solving "the problems" -- leukemia, tumors, AIDS. "I didn't enjoy hearing complaints about ill-defined backaches -- the sort of stuff that I'd now be the first to complain about. I didn't have the benevolence of some who are made to be with patients. I don't want to belittle it, but it just wasn't me. I had to have something that was an academic problem."

After a residency at the University of hicago, Gallo came to NIH in 1965. He felt a fearful symmetry when he was given, as his first assignment, a stint treating children with leukemia. "I thought of Judith." And for a while he bristled at the job. "I thought I was coming to the mecca of research, and I asked myself, 'What the hell am I doing here? I'm spending all my time making sure somebody wasn't dead.' "

He would soon leave clinical life for the laboratory, but not before he met a remarkable patient, a boy not much younger than Judith Gallo. "He had acute lymphatic leukemia, a beautiful kid around 5 or 6 years old, very intelligent with a way of getting under your skin." Gallo treated the boy with the sort of chemotherapy that was only in the experimental stages when his own sister was dying. "That little kid could take it so well. He combined a particular beauty and charm with the ability to take all the needles."

Years later, the cancer returned and the boy was dead. His name was Kent Ghost.

Gallo had always known that he could not stay in the clinic. "I don't like something I can't control, and you can't control the fact that many of these people are dying. There are too many failures. When I was out of the line of fire and in the lab, I had a colleague of mine who saw death all the time. He couldn't take it anymore. He went to a Holiday Inn and gave himself a bottle of morphine until he was dead."

Gallo could not bear a life so pressured. "I had to make a contribution in a different way," he says. "I wanted to help people, but I had to be somewhere away from the dying and the dead." THE SCIENTIFIC PROCESS IS A DARK labyrinth lined with distorting mirrors, deceptive points of light that suddenly burn out, trapdoors that lead to other labyrinths. "You grope along in the dark," Gallo says. And meanwhile, the world waits.

In Wiesbaden, Gallo describes what he and his colleagues have discovered so far in the labyrinth. The crowd is huge, spilling into the aisles and the corridor outside the hall. "It may be that not everyone in the world loves Bob," Kurth says, "but they'll go a long way to hear what he has to say."

Gallo begins with basics. That HIV, the AIDS virus, is a lying virus, one that attaches itself to T-4 cells, which coordinate the body's immune system. When confronted by the AIDS virus, the T-4 cell is something akin to a blind man fooled by a seductive thief. Thinking it is meeting something normal and friendly -- like hormones or other molecules necessary to the working of the immune system -- the T-4 cell extends a friendly chemical greeting. It lets the virus through its doors.

Once inside, the AIDS virus sheds its coat (an envelope of proteins) and begins to ransack its host. With the unwitting chemical cooperation of the T-4 cell itself, the virus begins to duplicate, making more and more virus, and, worst of all, destroys the integrity of the cell by letting loose strands of its own genetic information. The viral genes begin to intertwine with the T-4 cell's genes, producing a deadly new mix. Once this happens, the T-4 cell is no longer programmed as a healer. Now it is a killing machine. Eventually, sometimes years later, the viruses explode out of the cell and kill it. So far, little can stop the awful progress. "There is a kind of beauty in the way the virus avoids the body's defenses," Gallo says. "Terrible beauty." From there, the new viruses raid other healthy T-4 cells, and the process of deception and destruction multiplies.

As more and more cells are corrupted and destroyed, the body's ability to avoid disease all but disappears. Despite the help provided sometimes by experimental drugs such as azidothymidine (AZT), the AIDS victim awaits a roster of diseases that will likely kill him: Kaposi's sarcoma, Hodgkin's lymphoma, cloacogenic carcinoma, Burkitt's lymphoma.

Gallo projects a series of slides describing this narrative on a screen behind him. They seem like so many maps of battles lost.

"There will never be a cure for AIDS in the strictest sense," he says. "Maybe we'll find a vaccine."

To find a vaccine means unraveling the mystery of the way the virus and the cell first attach. To find a vaccine means stimulating the cell in such a way that it defends itself with antibodies against the virus.

The AIDS virus is a genius criminal, and it will take leaps of genius to defeat it. Recently, Gallo was crestfallen when he injected some chimps with an experimental virus; all the chimps got AIDS. It is painstaking work. A vaccine that is effective for one variation of the virus may not work for another variation. Gallo says he is betting that it will take a "cocktail" approach, a vaccine that takes into account enough variants to be effective. There is also a danger factor. Ordinarily, a vaccine uses a killed or weakened version of the virus itself in order to stimulate enough defenses so that when the real disease actually appears, it can be defeated. With AIDS, there is the danger that a vaccine's virus may not be quite weakened enough and will produce disease and disaster instead of defense.

AIDS research is not a science for the timid. The top researchers are attempting an immensely difficult task under the full heat of television lights and with scared, sometimes dying, voices whispering in their ears. At the international AIDS conference in Washington in June, doctors heard protests on the streets and the shouted questions of the press. When have scientists known such pressure? Jonas Salk, whose polio vaccine was the most celebrated scientific discovery of a generation, says the task "demands ego. There's no modesty involved." Gallo, for his part, says, "If you have no ego, how the hell are you going to find something? It takes a certain arrogance to say, 'You bet your ass I can solve the problem.' " GALLO IS IN PRIME POSITION TO FIND A virus. Not only does he have a record of success worthy of Salk, he also has known profound failure, and it is the wholeness of a scientist's experience that gives him his shape, his quality and strength.

Gallo's deepest failure came in the mid-'70s. He was trying to prove the presence of retroviruses in humans. Retroviruses, such as AIDS, have a kind of "backwards" genetic system. Instead of containing DNA, as most normal viruses do, they contain "messenger" RNA. An enzyme known as reverse transcriptase enables that RNA to become DNA when it enters host cells like the T cell. Gallo suspected that retroviruses could cause any number of diseases in man, but many of his colleagues were skeptical. "I knew I was right, but in science that means almost nothing." For years, he and his lab went through countless experiments of trial-and-error, most of them coming to nothing.

In 1975, Gallo believed he had discovered a retrovirus in a patient suffering from a form of leukemia. In order to characterize the virus, to analyze its components completely, he needed to grow it in mass amounts. He kept the growth factor for his virus in a refrigerator. One day, people in the lab discovered that the plug for the freezer had been pulled, and that the test tubes inside had been smashed. The growth factor was gone. The cells were gone. Years of work, gone. "It was sabotage, and I believe I know who did it," says Gallo, though he will not say whom he suspects.

The feeling of failure was excruciating. "It was a very depressing time for all of us," says Gallo. But he persisted, creating IL-2, a new growth factor for immune cells. Able now to grow the virus, Gallo seemed to turn a corner. "We got permanently growing cell lines eventually, and it was a great eureka. We succeeded 10 times in 10 different cell lines, and we thought we had made the discovery, the genuine article, that retroviruses exist in humans. A year or more of analysis went by. We thought it was a triumph."

It wasn't. It was a humiliating failure. To his astonishment, Gallo discovered that three of his viruses were not from humans at all. They were from monkeys. A baboon, a gibbon and a woolly monkey. His work was contaminated, a flop.

There was snickering in the halls of science, at least from those who did not like Robert Gallo. Some of his fellow scientists, Gallo believes, enjoyed his humiliation. He felt abandoned. "I was depressed. Dumbfounded. Angry. It was the low point of my whole career. It was almost the last nail in the coffin of the field of retrovirology. The program died, and all the good that came out of it, like interleuken-2, which would be so important fighting cancers, didn't seem to matter -- to me or to the world. I became more cynical, tougher, less happy. I mean, what could it be but sabotage? One contamination can occur, but three? In 15 years I had had one contamination from a mouse. But three? Please! I've never been so low." One of Gallo's colleagues, Robert Gallagher, was so profoundly disappointed that he left science for a while.

The period even put a strain on Gallo's marriage. "It was very sad for us," says Mary Jane Gallo. "I was hearing people say things about my husband, and it was a challenge to our marriage. I didn't understand Bob's needs at the time. So I kept my distance, not in a conscious attempt to move away but in an attempt to help him. How do you know the right thing to do? Everyone was affected. The two of us, our kids, our friends. It was turmoil all around."

Two years later, Gallo was able to prove conclusively the presence in humans of a retrovirus that causes a kind of leukemia. He called it HTLV-1. It was a magnificent triumph. He had endured years of failure, but he was right all along. In fact, had Gallo not gone on almost immediately into AIDS research, his colleagues say that HTLV-1 would have meant a Nobel Prize for him. "Now they're probably waiting a while," says one. "AIDS is the center of the medical universe." BEFORE LEAVING WEST GERMANY,

Gallo meets with the press in his hotel suite. A television team from Frankfurt sets up a veritable solar system of lights and reflectors. The process is endless, and so, finally, when the interviewer invites Gallo to sit on the couch and "talk a while," Gallo thinks he will have a chance to give at least a capsule form of his stump lecture.

The interviewer looks earnestly at Gallo and asks, "Tell us, can you get AIDS in the dentist's office?"

Gallo blinks. He answers, "Yes. But only if the dentist is infected and he bites you."

Out go the lights. Out goes the dim bulb of interest that had seemed to brighten the interviewer's eyes.

"Thank you, Doctor."

"You mean that's it?" says Gallo. "Are you joking? You came all the way out here to ask about dentists? Jee-sus. Well, that was the weirdest interview with the brightest lights."

Gallo lets nothing pass. He is the rare person who is constitutionally unable to keep his own counsel. After a day traveling with someone, he might reveal his deepest personal problems. Sometimes it is the reporter who must remind him that perhaps something is best left off the record. He is a naked, trusting soul, and, even when he lets loose with sarcasm, he seems to think that everyone will understand him. "He's a man of extremes, and not everyone understands that," says Mary Jane Gallo. "He can attack but he's incredibly vulnerable and insecure at times. He can be charming, but then he can just swallow other people up. Bob is always testing the people around him, even friendships. Sometimes he's thinking, 'If I expose myself, will I be taken advantage of. And if I'm taken advantage of, will I be able to take it?' "

Says Howard Temin, who was awarded a Nobel Prize in 1975 for his work on a link between viruses and cancer, "Bob arouses more strong emotions in other people than most other scientists."

"Bob thinks everyone is friend, or he wants it that way," says his colleague Dani Bolognesi. "A reporter will ask for a five-minute interview and Bob will treat him like an honored guest. He's open to the fullest, almost to the point of embarrassment."

But there are people who want more. Many of the reporters who meet with Gallo seem to want him to be someone he is not, a more stately figure, perhaps, one who finds the sideshows of science, the gossip and competition, to be unworthy of him. "What they don't understand is that we're all competitive," Bolognesi says. "You have to be in this game. There's only so much funding and so much room in the field. And AIDS is a field that's writing modern medical history. These are unparalleled diseases and times. You don't have the luxury to not be competitive."

In Europe especially, Gallo's reputation suffered immeasurably during his battle royale with Luc Montagnier of the Pasteur Institute. Simply put, the debate centered on who had discovered the cause of AIDS. After scientists diagnosed AIDS as a disease in 1981 and the Centers for Disease Control in Atlanta described some of its qualities a year later, Gallo and Montagnier, who had shared information freely for years, began a series of sharp volleys, scientific, legal and personal, that lasted until early this year.

In February 1983, Gallo proposed that AIDS was "probably" caused by a human retrovirus, "presumably" a variant of the original one that he had discovered. Seven months later, at a conference in Cold Spring Harbor, N.Y., Montagnier described a virus he called LAV. Montagnier's evidence was limited, but his conclusion that LAV is the AIDS virus would prove correct. At the conference, Gallo asked Montagnier a series of questions on the conclusiveness of the Pasteur Institute's claims. Gallo calls the questions "probing." Montagnier says they were "out of line."

"Montagnier was probably expecting to just give the lecture and get applause," Gallo says. Montagnier, speaking from Paris, says, "I gave a lot of evidence that we were on the right path, and I expected people to say, 'Oh, that's very good.' Instead, I got a sort of heart attack from Gallo's questions. Some of his criticisms were really out of . . . reality."

Gallo now says he knew since "1982 or so" what the virus was, but "knowing and proving are two different things." In May 1984, he not only grew the virus in mass quantities and nailed down once and for all the cause of AIDS (calling it HTLV-3 instead of LAV), he also introduced the so-called "western blot" blood test for detecting AIDS. He applied for a U.S. patent. Montagnier had also applied for a patent on a test of his own.

Thus began a long struggle for credit and patents, which, to many both inside and outside science, was an unseemly affair. When Gallo won the patent, the Pasteur Institute filed lawsuits claiming its lab was responsible for the new technology and should receive credit and possible profits. Even the cooperation between the labs in the early '80s became a source of suspicion. There were insinuations from the French, widely touted in the European press, that Gallo had stolen valuable information from Montagnier. Gallo claimed he had stolen nothing, and that Montagnier had never presented sufficient evidence to prove discovery of the AIDS virus. Charge and countercharge. It was an ugly spectacle, one that did no one any good except the lawyers.

At an AIDS conference in Paris last year, the furor was at such a pitch that hundreds of reporters sought Gallo for interviews. The European papers, high and low, were filled with anti-Gallo sentiment. "The tension in me was incredible," Gallo says. "I was disturbed, intense."

Just before Gallo was going to meet with the press, Jonas Salk took him into the men's room and told him to avoid the reporters.

"You'll get killed," Salk said. "You're too nervous. Who knows what you'll say?" Gallo, for once, followed instructions.

In the coming months, Salk and many others, including 17 Nobel Prize winners, urged a reconciliation. Salk knew how difficult it would be. "Something like this is like an illness in science, a psychosis. Something is out of order, people take sides. The patent issue set things off, but the coin of the realm was credit not money." Indeed, profits from a blood test would go to the U.S. Treasury or the Pasteur Institute for further research. No one was buying diamond rings with AIDS money. But credit was, and is, another thing. The search for credit is often intense -- it was in the aftermath of the polio vaccine -- but the tragedy of AIDS made it seem all the more craven. "The reward system helped make it that way," says Salk.

The greatest credit of all is the Nobel Prize. And now colleagues were telling Gallo that he was blowing his chance, that the Nobel committee would not want to get near such a debate. "Certainly the Nobel committee doesn't like this sort of dispute," Montagnier says. The two men now felt the forces demanding they settle their differences and go forward. And so at a meeting at Gallo's room at the Intercontinental Hotel in Frankfurt last year, Salk, Gallo, Montagnier and several colleagues collaborated on writing a chronology of who did what and when. "Monty brought a bottle of cognac to the room," says Gallo, "and I told him we wouldn't drink until we'd finished."

Once the settlement was signed and published in Nature, the storm clouds scattered. "Everything is sweetness and light," Gallo says with equal measures of irony and sincerity. "Everyone is relieved," says Montagnier. The settlement, which was formally announced last March 31 at the White House by President Reagan and French Prime Minister Jacques Chirac, provides that the French would drop their suits, that a new AIDS research foundation would get 80 percent of any profits reaped from the blood tests and that the AIDS virus would not be named LAV or HTLV-3, but rather HIV.

Lately, Gallo finds himself lunching at the French Embassy and consulting on the phone with Montagnier. Relations are not perfect, but they are workable. "For the last six months, the French have done everything for me short of giving me the Legion of Honor."

Perhaps the only ones not surprised by the pitch of competition were scientists. Dr. Genoveffe Franchini, who has worked in Gallo's lab for eight years, says that Gallo would invite his colleagues to his house on Sundays for some half-court basketball. "We would fight because Bob always wants to win so badly," she says. "He's almost unstoppable. He'd argue if the ball was in bounds or out. He just won't let go, even if he's wrong. And in the lab, believe me, it's not a child's game."

"My back's no good for basketball anymore," Gallo says. "I'll save my fight now for a vaccine." ::

CAPTION:Gallo at building 37, home of his aids lab.