CDC's Clinical Studies of Daily Oral Tenofovir for HIV Prevention
Anticipated Results and Impact
As eager as we are for data about this new approach for HIV prevention, results of the trial wont be available until sufficient data have been collected and analyzed to determine whether the drug is safe and effective. We are probably 2 to 4 years away from trial results. Independent panels of experts will monitor the trials closely so that the trials can be concluded as soon as definitive answers are available.
If tenofovir does prove to be effective at preventing HIV infection in this trial, how will the drug be made available to people who need or want it?
If the efficacy trials in Botswana and Thailand prove that the drug is effective, participants in these trials and their communities will be the first to benefit. All trial participants will receive tenofovir immediately and will continue to receive it for 1 year while CDC works with the Botswana Drugs Regulatory Unit and/or the Thai Food and Drug Administration for approval of use by the health care systems in these countries.
CDC is also working to determine how possible trial outcomes will influence future HIV prevention research, policy, and programs in the United States and worldwide. CDC will collaborate with its partners in the Department of Health and Human Services, the State Department, the Food and Drug Administration, and the World Health Organization to determine how to most effectively apply various potential results from these trials to real-world practice.
If tenofovir proves safe and effective in one population, will it work equally well in other populations?
CDC is conducting studies in different populations to help address this question. HIV is more readily transmitted through injection drug use than through sexual exposure. The virus is transmitted more easily during rectal intercourse than during vaginal intercourse. For these reasons, the efficacy of tenofovir in reducing HIV transmission in one population may not necessarily apply to other at-risk populations.
If studies show that tenofovir reduces the risk of HIV transmission, will people still have to practice other risk-reduction behaviors for HIV?
Yes. Regardless of the outcome, CDC will not recommend tenofovir as a first-line defense against HIV infection. Abstinence and mutual monogamy with an HIV-negative partner will remain the only 100% effective ways to prevent infection. However, if effective, this strategy could provide an additional safety net to sexually active persons at risk, when combined with reduction in the number of sexual partners, HIV counseling and testing, consistent and correct condom use, and other prevention strategies.
It is also important to remember that tenofovir will not prevent syphilis, gonorrhea, chlamydia, herpes, hepatitis, or other sexually transmitted diseases, many of which play a role in facilitating HIV transmission or speeding HIV disease progression.
Absolutely not. As we move forward with our search for new prevention strategies, it will be critical to determine how the approaches that are proven effective can best be integrated into programs. Effective behavior-change programs have greatly reduced the rate of HIV infection in the United States, and many other nations during the past 2 decades of the HIV epidemic. Because no strategy will be 100% effective in preventing HIV infection, their future impact will ultimately be determined by how effectively strategies are used in combination to provide the greatest protection to individuals at risk.
According to media reports, a small number of physicians in the United States and the United Kingdom are already using tenofovir in hopes of preventing HIV infection among patients in their practices. These physicians are doing so in the absence of clinical data demonstrating tenofovirs ability as a pre-exposure HIV prevention strategy.
That is why CDC is conducting these important trials -- to contribute to the work of scientifically evaluating the safety and efficacy of tenofovir in the prevention of HIV transmission among persons who are at risk.
This article was provided by U.S. Centers for Disease Control and Prevention. Visit the CDC's website to find out more about their activities, publications and services.