Ho, David Da-i (1952-…), is a Chinese-born physician who has conducted important research on the virus that causes AIDS. Ho’s research has provided new insights into how the virus, called human immunodeficiency virus (HIV), acts once it infects the body. This research has led to treatments that have improved the health of people infected with HIV and raised hope that a cure can be developed.
HIV belongs to a group of viruses called retroviruses. Scientists thought that HIV remained dormant (inactive) in the body for years after infection. They did not know why it took up to 15 years for HIV infection to develop into AIDS. Ho discovered that the virus actually reproduces itself rapidly once it infects a person, producing billions of copies of HIV. He found that the immune system destroys the virus almost as fast as the virus reproduces. During this time, infected individuals have little virus in their body and remain healthy. The continuous reproduction of HIV over many years, however, eventually exhausts and destroys the immune system. At this stage, an infected individual usually develops the symptoms of AIDS.
Ho thought that treatment with powerful antiviral drugs soon after infection, while the patient’s immune system remains healthy, can delay or possibly prevent the development of AIDS. This idea led to a treatment called Highly Active Anti-Retroviral Therapy (HAART), often called a “drug cocktail.” In this therapy, people infected with HIV begin taking several anti-HIV drugs long before they develop symptoms of AIDS. HAART can reduce the HIV in the body of most patients to amounts so small that the virus cannot be detected by medical tests, saving the patient’s immune system. The therapy has increased the life span of persons with HIV and decreased the number of deaths from AIDS in the United States and in other countries where the drugs are available and affordable.
The therapy does not, however, completely eliminate the virus from the body. Ho discovered that HIV can persist for years in certain cells of the body where it is not affected by the drugs. Patients must continue HAART indefinitely to remain healthy even though the treatment may cause serious side effects. Ho and other medical researchers are working to develop vaccines to prevent HIV infection, and new drug therapies that may lead to a cure.
David Ho was born Ho Da-i in Taichung, Taiwan, on November 3, 1952. He came to the United States with his family in 1965, and his father changed his name to David. In 1974, he received his Bachelor of Science degree in physics and biology from the California Institute of Technology. He earned his M.D. from Harvard University in 1978. Ho held several teaching and research posts before 1990, when he became director of the Aaron Diamond AIDS Research Center in New York City.
See also AIDS ; Antiviral drug .
