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February 27, 2011


Using Pre-Exposure Prophylaxis (PrEP) as a Prevention Tool for MSM: The Promise Comes with Challenges

By Ronald Valdiserri, M.D., M.P.H, Deputy Assistant Secretary for Health, Infectious Diseases, U.S. Department of Health and Human Services


Dr. Ronald Valdiserri

On Saturday, February 26th, I attended a day-long meeting organized by the Centers for Disease Control and Prevention (CDC) and hosted by the Fenway Community Health Center in Boston. The theme of the meeting was “Moving forward with PrEP Implementation.” Meeting participants included researchers involved in the original iPrEX study and other ongoing HIV prevention studies, health care providers caring for men-who-have-sex-with-men (MSM), state and local health department program directors, MSM community advocates, policy experts, and federal officials.

The meeting began with a detailed review of the iPrEx study, which included nearly 2,500 participants from Peru, Ecuador, Brazil, Thailand, South Africa, and the United States. Participants were MSM engaging in high-risk sex with other men—including a small number of transgender women who reported high-risk sex with men. The study findings, released in November 2010, showed that sexually active MSM who took a once-daily pill containing 2 anti-HIV drugs were 44% less likely to become infected with HIV, compared with participants who took a placebo.

Because iPrEx was a “blinded” study, participants did not know if they were receiving active drugs or placebos (inactive drugs). As such, all study participants received intensive risk-reduction counseling. Along with this counseling, all study participants also received monthly HIV testing, condom provision, and treatment for other acquired sexually transmitted diseases.

When these results were summarized at the Saturday meeting in Boston, the audience was reminded that the level of protection experienced by study participants who received the active drug varied widely, depending upon how consistently they took their daily pills. For those who took the daily drug at least 90% of the time, HIV risk was reduced by 73%. Others, who took the drug less frequently, had only a 21% reduction in HIV risk. Given this finding, a significant theme of our discussion in Boston was the critical role that adherence counseling must play in any future efforts to develop and implement PrEP programs for MSM.

The U.S. Public Health Service is currently at work on guidelines for PrEP use among MSM. In the meantime, CDC has released interim guidance, as well as a fact sheet on Pre-Exposure Prophylaxis for HIV Prevention (PDF). But, as our meeting in Boston highlighted, there are many critical questions that must be answered before we can move this important prevention research finding from the pages of a scientific journal and into the day-to-day lives of MSM who are at high, ongoing risk for HIV infection. Several of the major questions raised by participants were:

  • Among the diverse communities of MSM in the U.S., what subset of men would be the most appropriate candidates for this new prevention tool?
  • Given the disproportionate burden of HIV infection among MSM of color—many of whom also live at or near the poverty level—how will daily drug treatments be financed?
  • In the real world of competing needs and resource constraints, how should PrEP programs for MSM be combined with other prevention approaches for MSM to result in the greatest pay-off in terms of decreasing new HIV infections?
  • How do we build the needed capacity among medical providers, health departments, and community-based organizations so that PrEP can be implemented as part of a comprehensive package of HIV prevention services for MSM at risk for HIV?
  • Could PrEP serve as a “gateway” into other equally effective—and perhaps less costly—prevention approaches for MSM?

While everyone at the Boston meeting recognized the promise of this new tool, there was a general consensus that PrEP is not a “magic bullet” and that it should not be viewed as the sole approach to reducing new HIV infections among MSM.

Moving forward with discussions about how to implement PrEP as a new prevention strategy for MSM, let’s keep in mind the necessity of supporting combined biomedical, behavioral, and structural approaches—all of which are called for in the National HIV/AIDS Strategy. Given the ongoing burden of new HIV infections among MSM communities in the United States, we are obliged to carefully examine our current approaches and, when called for, make changes in where and how we deliver our HIV prevention services.

November 23, 2010


President Obama Welcomes New HIV Prevention Research Results

Cross-posted from The White House, Office of the Press Secretary

WASHINGTON, D.C. – Today, the National Institutes of Health announced findings on recent HIV prevention research.  The study finds that a daily dose of an oral antiretroviral drug taken by HIV-negative gay and bisexual men reduced the risk of acquiring HIV infection by 43.8 percent, and had even higher rates of effectiveness, up to 73 percent, among those participants who adhered most closely to the daily drug regimen.

“I am encouraged by this announcement of groundbreaking research on HIV prevention. While more work is needed, these kinds of studies could mark the beginning of a new era in HIV prevention. As this research continues, the importance of using proven HIV prevention methods cannot be overstated,” said President Obama.

One of the President’s top HIV/AIDS policy priorities was the development and implementation of a National HIV/AIDS Strategy (NHAS), which was released in July 2010. As underlined in the NHAS, no HIV prevention method is 100 percent effective, and a combination of approaches including, among other steps, consistent condom use, will be necessary to prevent HIV infection.  Nevertheless, the research results announced this past summer of an effective microbicide and today’s results fall directly in line with priority recommendations in the NHAS.  Moreover, today’s study suggests that antiretroviral medication may serve as one more valuable tool as we seek to develop the best combinations of effective approaches to prevent HIV infecti

July 30, 2010


NIH-Led Scientists Find Antibodies that Prevent Most HIV Strains from Infecting Human Cells

By Laura Sivitz Leifman, National Institute of Allergy and Infectious Diseases, NIH

Scientists have discovered two potent human antibodies that can stop more than 90 percent of known global HIV strains from infecting human cells in the laboratory. The scientists also have demonstrated how one of these disease-fighting proteins accomplishes this feat. According to the scientists, these antibodies could be used to design improved HIV vaccines, or could be further developed to prevent or treat HIV infection. Plus, the method used to find these antibodies could be applied to isolate therapeutic antibodies for other infectious diseases as well.

Led by a team from the NIAID Vaccine Research Center (VRC), the scientists found two powerful antibodies called VRC01 and VRC02 in an HIV-infected individual's blood. They discovered the antibodies using a probe they developed that homes in on the specific cells that make antibodies against a very vulnerable spot on HIV.

Continue reading "NIH-Led Scientists Find Antibodies that Prevent Most HIV Strains from Infecting Human Cells" »

July 20, 2010


International AIDS Conference Day 3: Research Highlights

by Dr. Ron Valdiserri, Deputy Assistant Secretary for Health, Infectious Diseases, U.S. Department of Health and Human Services


Dr. Ron Valdiserri

Dr. Anthony Fauci, Director of the National Institute of Allergy and Infectious Diseases, shared the latest scientific information with the conference delegates about the actual steps that the human immunodeficiency virus (HIV) takes when it makes contact with the human genital tract (through exposure to semen or vaginal secretions) which result in infection.Understanding, in detail, the early steps taken by the virus to establish infection is very important because it provides scientists with targets for the development of new drugs and potential vaccine candidates. Recent work has identified a special subset of CD4+ cells that are especially susceptible to HIV infection. With this discovery, scientists can now begin to develop strategies to block the virus, with the hope that such treatments could, in the future, successfully prevent HIV infections.

Dr. Everjoice Win Exit Disclaimer , the Head of Women’s Rights at ActionAid International Exit Disclaimer in Zimbabwe, spoke on the critical issue of gender-based violence against women and girls. She emphasized why it is essential to understand how violence and the fear of violence can impact all aspects of HIV/AIDS prevention, diagnosis, and treatment programs for women and girls. Dr. Win urged policy makers and leaders around the world to recognize “women’s rights” as human rights and urged better surveillance of gender-based violence and improved interventions for preventing it.

Tuesday afternoon, Drs. Quarraisha and Salim Abdool Karim, two well-known AIDS researchers from South Africa, released the results of their long- awaited study on a vaginal gel containing the antiretroviral drug, tenofovir. For the first time ever, a vaginal gel has been shown to significantly reduce the transmission of HIV. This landmark study, which enrolled nearly 900 South African women, was shown to reduce HIV transmission by 39%--compared to a placebo gel that did not contain the antiretroviral drug.This announcement was widely acclaimed by conference delegates as a significant step forward in HIV prevention for women around the world.

Watch a video recording of today's opening plenary Exit Disclaimer .

October 09, 2009


Renewed Hope for an HIV Vaccine

By Dr. Carl W. Dieffenbach

Carl W. Dieffenbach, Ph.D

Carl W. Dieffenbach, Ph.D

In late September, the U.S. federal government announced news on HIV vaccine research that sparked interest around the world. A trial called RV144, or the Thai HIV vaccine clinical trial Exit Disclaimer, showed that the experimental vaccine regimen was safe and about 31 percent effective in preventing HIV infection. Although the vaccine regimen had a very modest effect (typical vaccines for other disease and conditions provide about 80-90 percent protection), it is the first HIV vaccine to demonstrate any ability to reduce the risk of HIV infection in people. Since the discovery of HIV, making a vaccine has been a major scientific goal of AIDS researchers. Until now, the field has been paved with setbacks and disappointments including two trials that were stopped in 2007 due to safety concerns. This new result reminds us that science is about finding answers and to do this, we must continue to conduct research.

Continue reading "Renewed Hope for an HIV Vaccine" »


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