April 20, 2009
"In the absence of a vaccine, three bold new approaches to controlling the HIV/AIDS pandemic are being discussed by those working in medicine and public health. These approaches are still in the conceptual and testing phases, but if applied as a group, it's possible they could have a dramatic effect.
"The first approach would provide a daily dose of antiretroviral medicines to people who are not infected with HIV but are at high risk of becoming infected. This strategy, known as pre-exposure prophylaxis, or PrEP, is based on the concept that blocking HIV's replication immediately after exposure to the virus may prevent infection.
"The National Institutes of Health and other organizations are conducting clinical PrEP trials among various at-risk populations. Initial findings are expected later this year.
"The second approach would involve universally available, voluntary, annual testing for HIV infection and immediately providing antiretroviral therapy to those who test positive. The potent combinations of antiretroviral medicines available today can suppress the amount of HIV in an infected person's body to extremely low levels, resulting in longer lives and better health. Plus, it has been clearly shown that those who have less HIV in their blood are less infectious to others.
"New modeling research suggests that implementing a voluntary 'test and treat' approach could dramatically reduce new HIV cases beginning within a decade and ultimately halt the pandemic.
"Before this approach can be implemented, however, we must pursue a research agenda that includes studies of feasibility, efficacy, the benefits to individual patients vs. the benefits to society, and cost-effectiveness.
"The third approach might entail purging all vestiges of the virus from a person's body, a difficult challenge. Perhaps more likely, though still difficult, would be a 'functional cure' -- therapies that suppress the virus to such low levels that an HIV-infected person would no longer need treatment because his or her immune system could keep the residual virus in check. The latter result would be more likely if therapy were initiated early in the course of infection, when significant immune function remains. The NIH plans soon to launch an initiative designed to solicit novel ideas for an HIV cure from the scientific community."
The author is director of the National Institutes of Allergy and Infectious Diseases.