(BlackDoctor.org) — Two clinical trials conducted in three African nations demonstrated for the very first time that daily antiretroviral (ARV) drug therapy can dramatically reduce the risk of HIV infection for heterosexual couples. The results were announced Wednesday by the Centers for Disease Control and Prevention (CDC). The “groundbreaking findings” in HIV biomedical prevention provide additional evidence that medications originally developed to save lives also offer a powerful way to prevent new infections. This strategy of providing daily ARVs to uninfected people to reduce their risk of HIV infection is called pre-exposure prophylaxis (PrEP).
PrEP offers a new strategy to prevent HIV cases acquired through heterosexual contact — the epidemic’s primary method of global transmission and a disproportionate factor in Black America.
“I was very excited to hear the results,” says Dazon Dixon Diallo, M.P.H., founder and president of the Atlanta-based Sister Love, an AIDS and reproductive-justice organization targeting Black women worldwide. “These two studies are the only two we know that are giving feedback on biomedical prevention for women. This is a real prevention option.”
The smaller study, known as TDF2, included about 1,200 sexually active, HIV-negative men and women in Botswana. The research, funded by the CDC, found that taking a once-daily tablet of the ARV Truvada — a combination of the drugs tenofovir and emtricitabine, sold by pharmaceutical company Gilead Sciences — reduced the risk of acquiring HIV infection by roughly 63 percent.
The second study, known as Partners PrEP, recruited 4,758 sero-discordant couples — those in which one partner has HIV and the other does not — in Kenya and Uganda. The uninfected partners were randomly assigned to take either Truvada, Viread — an ARV containing only tenofovir, also marketed by Gilead — or a placebo. The HIV-negative partners taking Truvada saw their infection risk drop by 73 percent, while those taking Viread saw theirs drop by an average of 62 percent.
The Partners PrEP findings were so conclusive that researchers ended the trials early because it would have been “unethical” to continue providing participants with placebos. Partners PrEP was conducted by researchers from the University of Washington and funded by the Bill and Melinda Gates Foundation.
The two new studies restore confidence in PrEP’s potential to reduce HIV infections among women and heterosexual couples. Earlier this year, researchers reported poor results from a similar study conducted in Kenya, South Africa and Zimbabwe.
“The results have particular significance for Black women in the United States [because] the vast majority [who get] infected by HIV [are infected] through heterosexual transmission,” says Kevin Fenton, M.D. Ph.D., director of the CDC’s National Center for HIV/AIDS, Viral Hepatitis, STD and TB Prevention.
“PrEP would provide women with a much-needed way to prevent HIV that they can control for themselves, rather than relying on a male partner to use a condom,” he says. “Especially for women who may be in situations where they are not able to negotiate condom use, this type of prevention method — controlled solely at the discretion of the person taking the pills — would be very important.”