Dr David Ho Da I witnessed the birth of AIDS and ever since has devoted his life to its cure and, latterly, its prevention. He was born in Taiwan, but immigrated to the United States of America at the age of 12 with his mother and younger brother to join his father who had already worked in the United States for 9 years. He grew up in Los Angeles and received his Bachelor of Science degree in Physics from the California Institute of Technology. Four years later he gained his MD from the Harvard Medical School. He did his clinical training in internal medicine and infectious diseases at the UCLA School of Medicine and Massachusetts General Hospital. It was during his work in Los Angeles in 1981 that he came into contact with some of the first reported cases of what was later identified as AIDS. This was a turning point in his life and it was then that he determined to devote himself to dealing with this new and frightening disease that attacks the human immune system with such devastating effect. He has not wavered from that task.
Dr David Ho would be the first to admit that he is just one of a global team striving to cure or at least alleviate the effects of HIV and AIDS. It was David Ho, however, at times working alone, at times working with colleagues, who fundamentally changed the way scientists looked at the AIDS virus. His breakthrough work in virology, beginning in the mid-1980s, revealed how HIV mounts its attack. He tenaciously pursued the HIV virus in the first weeks of infection and carried out groundbreaking research into how the virus ultimately overwhelms the immune system. This work had the important effect of concentrating treatment and research away from the later stages of the illness to the critical early stages of infection. It was in this respect that his pioneering experiments with protease inhibitors proved invaluable. It had been thought that nothing much happened after the HIV virus entered the body. It simply lay low within the system's T cells - the linchpins of the bodies defence system - for anywhere between 3 and 10 years. Then something - as yet unknown - occurred to make the microbial invader awaken as AIDS. Each case, although appearing different, had one thing in common. Whatever was making people sick was singling out the T cells for destruction so that, eventually, the body's battered defences could not shake off even the most innocuous microbial intruder.
In 1989 David Ho joined academia at the UCLA School of Medicine and continued resolutely to pursue his research. Using the newly-available tool of genetic engineering - the PCR test used most famously in the OJ Simpson trial - David Ho's research soon showed that there were very high levels of virus in the first few weeks of infection; in fact, results showed that every day HIV produced not thousands, not millions, but billions of copies of itself and every day the body was required itself to launch billions of immune cells to counter the threat. It was little wonder that the immune system eventually crashed. What was so puzzling, however, was that, within a few weeks after the initial infection, the viral load plunged to low and, in some cases, undetectable levels. Patients recovered and seemed healthy.
Then came a significant career move. Philanthropist Irene Diamond founded the Aaron Diamond AIDS Research Center in New York and invited the 37 year old David Ho to be its director. It is now the world's largest private HIV/AIDS research centre. David Ho embraced the new challenge and concentrated his research on what happened during those middle years of relative good health. Confounding conventional wisdom, he believed that the answer to this puzzle would radically change the way HIV positive patients were treated. Protease inhibitors were now being applied to some effect and shut down viral production almost completely. But almost was not good enough. It often took less than a month for a few viral particles to mutate into a strain that was resistant to protease inhibitors. Ho surmised that, by combining protease inhibitors with the old standby drug AZT and a third drug called 3TC, HIV would struggle to undergo the three mutations necessary to resist combination therapy. The HIV cocktail was born and it proved an important breakthrough in HIV treatment. Since 1996 AIDS mortality in richer nations has declined spectacularly and David Ho can claim much credit for this success.
In 1996 David Ho was named "Man of the Year" by Time Magazine. In deciding upon the choice managing editor Walter Isaacson said: 'The purpose of Man of the year is to fulfill Time's basic mission of telling the history of our time through the people who make it. The choice of Dr Ho is a perfect example. Dr Ho did not make the most headlines but he helped to make history. We'll look back on 1996 as the year when we finally made progress against a plague that has been frightening the world for more than a decade.
There is, however, still a long way to go. In the words of David Ho:
"We cannot continue just to treat patients as they become infected. By developing a drug to treat the infected we could reduce mortality and morbidity. However, the real solution to the epidemic is to curtail the spread of the virus and that is done by education and through implementation of measures that would block transmission such as the use of condoms and preventing needle exchange. It can, however, be achieved most effectively if we could come up with a good vaccine that would block transmission. As a scientist I consider that to be our major mission".
Although combination therapy is effective, it is not a complete cure. It is also expensive and still out of the reach of many of the world's sufferers. David Ho has been working on a vaccine for several years and it is our most earnest hope that he is successful in this vital mission. He is now also heading a consortium of Chinese and American organizations to help address the problem of AIDS in China.
At birth Dr David Ho was given the Chinese name "Da-I" two ideograms which literally mean "Great One", a Taoist term of considerable cosmological consequence. It is a name reflecting great expectations. Those great expectations have been amply fulfilled.
Mr Chancellor, it is my honour and privilege to present Dr Ho for the award of the degree of Doctor of Science honoris causa.
Citation written and delivered by Professor Michael Wilkinson, the Public Orator.
