(3 of 9)
It wasn't the first time that Ho had overturned conventional wisdom. During the past 15 years, he has demonstrated an uncanny ability to ask questions that seem obvious only in retrospect and to probe key issues others have overlooked. It's a trait that does not endear him to some of his rivals. A few have accused Ho of being a publicity seeker who is giving AIDS patients false hope. Upon examination, however, most of the accusations appear to spring from professional jealousy. "David is the type of individual whom I feel particularly good about when he achieves success," says Dr. George Shaw, one of Ho's strongest competitors, who runs a state-of-the-art AIDS research laboratory at the University of Alabama in Birmingham. "He is a stellar scientist."
Ho has an extraordinary knack for being in the right place at the right time. Two years after he received his M.D. from Harvard Medical School, Ho witnessed the birth of the AIDS epidemic. He remembers how baffling it seemed.
The year was 1981, and Ho was chief medical resident at Cedars Sinai Hospital in Los Angeles. Across town at UCLA, Gottlieb had identified a new syndrome that seemed to target gay men. Each of the cases was different, but all had one thing in common: whatever was making the men sick had singled out the T cells for destruction. Eventually the body's battered defenses couldn't shake off even the most innocuous microbial intruder. The men were dying from what doctors termed opportunistic infections, such as Pneumocystis pneumonia, which attacks the lungs, and toxoplasmosis, which often ravages the brain.
Ho began seeing more and more of these patients in the intensive-care units at Cedars Sinai. Some doctors thought that poppers and other recreational drugs triggered the immune collapse. Others believed it was a bizarre allergic reaction from having too many sex partners. But Ho fell into the camp that suspected a virus. He quickly decided to specialize in AIDS research. "David was clearly a big thinker even then," says Dr. Mark Ault, who was a resident at Cedars Sinai at the time. "But that didn't stop us from kidding him about how he was always looking for gay men."
Ho ignored the gibes and in 1982 landed in Martin Hirsch's virology laboratory at Massachusetts General Hospital in Boston. A prominent scientist in his own right, Hirsch is known for cultivating talented young researchers.
Like many other ambitious young scientists, Ho wanted to be the first to isolate the virus that causes AIDS. Luc Montagnier and Robert Gallo beat him to it. (Ho came in fourth, after Jay Levy of the University of California, San Francisco.) Still, while working in Hirsch's lab, Ho became expert at detecting HIV in places where few were able to find it. He was the first to show that it grows in long-lived immune cells called macrophages and among the first to isolate it in the nervous system and semen. Just as important, he showed that there isn't enough active virus in saliva for kissing to transmit the infection. "David had the Midas touch," Hirsch recalls. "Whatever he did worked."