HIV, the virus that causes AIDS, is unique among disease-causing organisms, explained NIAID director Dr. Anthony Fauci at a Contemporary Clinical Medicine: Great Teachers Grand Rounds Lecture in Masur Auditorium on Sept. 11. As with polio, measles or smallpox, most people eventually recover from their initial infection. However, unless they’re treated with anti-retroviral drugs, nearly everyone infected with HIV dies.
The immune system’s inability to naturally mount a long-term response against HIV is the principal obstacle to developing an effective vaccine against the virus, said Fauci, whose talk was titled “HIV/AIDS: Much Accomplished, Much to Do.”
Fauci began his NIH career as a fellow at NIAID, studying atypical immune diseases. While he enjoyed his work and made significant discoveries, he hadn’t been able to follow his passion. “My real love of infectious disease and global health issues was not satisfied,” he said.
That changed when he first read about homosexual men with Pneumocystis pneumonia, an opportunistic infection found in patients with weakened immune systems, in the Center for Disease Control’s Morbidity and Mortality Weekly Report in the summer of 1981.
“I made a momentous decision at the time to essentially stop doing the things that I had been doing,” Fauci explained, “and to focus all of my attention on this new disease.”
NIAID director Dr. Anthony Fauci delivers a recent Contemporary Clinical Medicine: Great Teachers Grand Rounds Lecture.
Photo: Bill Branson
Since Fauci put together NIH’s first AIDS research group, scientists have made great advances in AIDS research. These include: understanding the life cycle of the virus, developing an arsenal of drugs to suppress it and slowing its spread with tools of prevention.
“When we first started taking care of people without any antiretrovirals, the median survival for a patient with AIDS was 6-8 months. Now, if you treat someone with HIV infection in their 20s, early in the disease, you can mathematically project they will live an additional 50 or more years,” Fauci said.
What frustrates him, though, is the challenge of identifying individuals who don’t know they have an HIV infection and the difficulty of getting many patients to adhere to antiretroviral therapy.
“We know that when you treat HIV-infected individuals, they don’t infect others,” Fauci said. “We can wipe out half of the infections merely by identifying the people who are infected and putting them on therapy.”
Treatment of uninfected individuals can also prevent HIV transmission. To illustrate his point, Fauci cited a recent study that looked at the use of pre-exposure prophylaxis of an uninfected sexual partner in a relationship in which one partner is infected and the other is not. The idea is to have people who do not have HIV (but are at high risk for infection) take a daily antiretroviral drug to reduce their risk. The study found 100 percent effectiveness for patients who took their pill every day. But in other studies of a similar approach, efficacy rates ranged from as low as zero to 44 to 75 percent in various populations.
“If you go to the trial in which efficacy was 44 percent—if you actually looked at only those people who took their drugs—the efficacy was over 90 percent,” Fauci explained. “People are not adhering to something that works.”
Despite these obstacles, Fauci noted that the research efforts against AIDS have produced considerable success. Not only has life expectancy of people with HIV been greatly extended, but also, in many developed countries, transmission of HIV from mother to child is less than 2 percent. Fauci noted that an estimated 4.2 million lives were saved by antiretroviral therapy in low- and middle-income countries over the last decade and well over 1 million infections in infants have been averted by providing antiretroviral drugs to HIV-infected mothers.
“When we go before Congress and talk about ‘What does the investment in basic research get you?’, this is about as good an example as anything we’ve ever done,” he said.