Top AIDS expert hopeful for vaccine

While he doesn't know if or when a vaccine for AIDS will be found, Microbiology Professor Emeritus Neal Nathanson says he's optimistic about current research efforts into fighting the disease. Nathanson, 71, was a vice dean at the Penn Medical School until this summer, when he headed south to become director of the Office of Aids Research at the National Institutes of Health, in Bethesda, Md. He returned to campus Thursday afternoon to speak to more than 160 people in the first of a series of monthly seminars hosted by the Center for AIDS and HIV Research, a research group which also seeks to increase public awareness of AIDS. Nathanson -- who also chaired Penn's Microbiology Department for 15 years -- discussed the difficulties of creating an AIDS vaccine as well as the fact that the creation of an effective and safe treatment for the disease "presents a much more difficult challenge than did the development of viral vaccines currently in the United States." For many viruses, he explained, a single infection confers lifelong immunity, an outcome he described as the "gold standard." But with HIV, the virus that causes AIDS, this is complicated by the persistence of the initial infection and the virus' long incubation period. As a result, Nathanson argued for the necessity of studying weakened versions of HIV, such as HIV-2, that may confer immunity from the disease. Though the weakened virus does not always prevent AIDS, he believes that it would be a mistake to discount the idea of using HIV-2 as a preventive treatment merely because the world is waiting for a "perfect vaccine." "We don't have anything that comes close," Nathanson said. More than half of the test subjects with HIV-2 did not develop AIDS. The longest running study of HIV-1, however, showed that 98 percent of test subjects became stricken with the syndrome. "There may be different ways of getting a vaccine," Nathanson said, noting that use of a weakened form of the virus may not be the only path toward immunization. "We shouldn't look for a single holy grail approach." To get a first-hand understanding of the epidemic's spread abroad, Nathanson visited the AIDS-stricken country of Uganda three weeks ago. Ten percent of that country's population has died of the disease, Nathanson noted, 100 times the rate in the United States. Additionally, few Ugandans can afford to pay the $5,000 in medical costs for treatment to slow the disease. Nathanson served on the AIDS Vaccine Committee last year that was commissioned by President Clinton -- who has publicly called for a vaccine by the year 2007 -- and chaired by Nobel laureate David Baltimore. Forced to confront AIDS' dark realities, Nathanson pointed out that lessons can be taken from the polio virus. In 1945, leading researchers felt a vaccine would never be discovered; a decade later, one was found. "We will eventually have a vaccine, though I don't know when," Nathanson said. Although his new job brings him closer to the Washington, D.C. area, Nathanson still lives in Philadelphia and his wife works at Penn's Dental School. "It is very nice that Penn had a person like Neal who built the AIDS community here," said Ronald Collman, a former student of Nathanson's and a professor of pulmonary and critical care at the Medical School. "Now, he can build an AIDS community in the country."