ARVs Taken By HIV- Partners Can Reduce HIV Transmission


NAIROBI, 14 July 2011 (PLUSNEWS) –
In bid to consider the effectiveness of pre-exposure prophylaxis (PrEP) for HIV prevention, 4,758 HIV-negative people in Kenya and Uganda were involved, all with HIV-positive partners.

One-third of HIV-negative participants took a daily tablet of the antiretroviral, tenofovir; one-third a combination of tenofovir and emtricitabine; and the rest a placebo. The trial, begun in July 2008 and conducted by the University of Washington’s International Clinical Research Centre, ended a year early due to the overwhelming evidence produced.

__________________________________________

ARVs Taken By HIV- Partners Can Reduce HIV Transmission

__________________________________________

A new study has added to growing evidence that a daily dose of antiretroviral treatment taken by the HIV-negative partner in a heterosexual, HIV-discordant relationship can significantly reduce the risk of HIV transmission.

The Partners PrEP trial [ http://depts.washington.edu/uwicrc/research/studies/PrEP.html ], the largest to date to consider the effectiveness of pre-exposure prophylaxis (PrEP) for HIV prevention, involved 4,758 HIV-negative people in Kenya and Uganda, all with HIV-positive partners. One-third of HIV-negative participants took a daily tablet of the antiretroviral, tenofovir; one-third a combination of tenofovir and emtricitabine; and the rest a placebo. The trial, begun in July 2008 and conducted by the University of Washington’s International Clinical Research Centre, ended a year early due to the overwhelming evidence produced.

“We found that the people [taking] tenofovir… had an average of 62 percent fewer HIV infections than those [taking] the placebo… while participants [on] the combination… had 73 percent fewer infections than those [on] the placebo,” Jared Baeten, lead investigator of the trial and assistant professor of global health and medicine at the University of Washington, told IRIN/PlusNews.

Participants in all parts of the study were offered a comprehensive HIV prevention package before and during the trial. Adherence to the daily PrEP medication was very high, with more than 97 percent of dispensed doses taken.

A second study conducted by the US Centers for Disease Control released similar results on 13 July. Named TDF2, it involved 1,200 heterosexual men and women in Botswana and found that 62.6 percent fewer HIV infections had occurred in participants taking a combination of tenofovir and emtricitabine compared with the placebo group.

“These results show that it is time for national governments to evaluate and incorporate PrEP into HIV policy,” said Baeten.

The study will be completed as investigators continue to monitor participants’ tolerance of the drugs; the participants on the placebo will be placed on ARVs.

Evidence

In May, a major randomized clinical trial found that treating [ http://www.plusnews.org/report.aspx?ReportID=92710 ] an HIV-infected individual can reduce the risk of sexual transmission of HIV to an uninfected partner by as much as 96 percent. In 2010, the Centre for the AIDS Programme of Research in South Africa (CAPRISA) [ http://www.plusnews.org/report.aspx?reportid=89895 ] found that a vaginal gel containing tenofovir was 39 percent effective in reducing a woman’s HIV risk when used for about three-quarters of sex acts and 54 percent effective when used more consistently. Also in 2010, the Iniciativa Profilaxis Preexposicion or Prexposure Prophylaxis Initiative (iPrEx) study [ http://www.plusnews.org/report.aspx?reportid=91180 ] found that daily oral PrEP reduced HIV infection risk among men who have sex with men and transgender people who took a combination of tenofovir and emtricitabine by an average of 43.8 percent.

“Our study reaffirms the importance of the argument for treatment as prevention; we are not pitting prevention against treatment – the two can work together to change the epidemic in a way that they couldn’t individually,” Baeten added.

Handle with care

Nelly Mugo, one of the study’s Kenyan investigators, said moving PrEP from research to policy needed to be handled carefully.

“The challenge is to find the people most at risk; it’s not like iodine in salt – ARVs are not for everyone,” she told IRIN/PlusNews. “NASCOP [Kenya’s National AIDS and Sexually transmitted infections Control Programme] needs to think keenly about how to find and target people at risk without creating stigma.”

Mugo further emphasized that for treatment as prevention and PrEP to work, it would be imperative for more people to be tested for HIV. “Currently, [fewer] than 60 percent of Kenyans know their HIV status; those numbers have to go up in order to know who is HIV-positive and needs to start on ARVs earlier and who is HIV-negative but at high risk and needs to start taking PrEP,” she said.

“Overall, the findings are very exciting and PrEP is a wonderful package, but it needs to be rolled out with care.”

Research continues into the effectiveness of PrEP, with investigators in the 5,000-women, five-arm Vaginal and Oral Interventions to Control the Epidemic (VOICE) [ http://www.mtnstopshiv.org/node/3437 ] trial saying it would continue as designed as they evaluate the Partners PrEP and TDF2 trial results. The investigators note that while the results are encouraging, they raise more questions about what happened with FEM-PrEP [ http://www.plusnews.org/report.aspx?reportid=92514 ], a three-country study that was halted in April 2011 after daily doses of a combination of tenofovir and emtricitabine failed to prevent HIV infection in participating women.

UNAIDS and the UN World Health Organization have hailed the results of the Partners PrEP and the TDF2 study, with Michel Sidibé, executive director of UNAIDS, saying the studies could “help us to reach the tipping point in the HIV epidemic”.

UNAIDS and the World Health Organization have already been working with countries in sub-Saharan Africa, Latin America and Asia to explore the potential role of PrEP in HIV prevention.

“In Kenya and Tanzania we have held regional stakeholders’ meetings to discuss the potential role of PrEP should the results of these trials be positive,” Kate Hankins, chief scientific adviser to UNAIDS, told IRIN/PlusNews. “In Kenya in particular, we will now be looking at where and how we can use PrEP; whether to integrate it with male circumcision, or to use it in PMTCT with HIV-negative male partners of pregnant women… it will take some thinking.”

Advertisements

5 Responses

  1. its a good input especially for discordant couples

  2. I am concerned about the ethical issues. There must have been a significant number of people on placebo who got infected for you to conclude that the PrEP works. How were these people explained to that they were at risk of HIV infection. Was it a double blind study. Did they know they were taking placebo?

    • Yes, this was a double-blinded study. Participants were aware that there was a chance they were to be assigned placebo. Entry into the study included a comprehension assessment to ensure that participants understood placebo and blinding.

      Best,

      Jared Baeten.

  3. At the time of enrollment, each participant was informed that once enrolled, we the researcher and they as participants would not know what drug they were taking
    The tablets all looked the same, but there were three possibilities, they could be taking the placebo (with no medication); Tenofovir ; Truvada
    we advised the couples to use condoms and provided them free condoms, also recognizing that at the time of enrollment, we did not know if these drugs would work to prevent HIV-1 infection.
    As we continue to follow up the participants, we are reminding them that Truvada and Tenofovir do not prevent HIV infection 100% and it is still important for them to continue using condoms.
    The results from Partners PrEP were in the context of providing condoms, advising on male circumcision and treating sexually transmitted diseases.

    Dr. Nelly Mugo

  4. […] ARVs Taken By HIV- Partners Can Reduce HIV Transmission (ladyenews.wordpress.com) Eco World Content From Across The Internet. Featured on EcoPressed 7 ways the military is embracing cleantech Share this:TwitterFacebookEmailPrintMoreLinkedInRedditDiggStumbleUponLike this:LikeBe the first to like this post. This entry was posted in Uncategorized and tagged AIDS Vaccine Advocacy Coalition, Centers For Disease Control And Prevention, Food and Drug Administration, Pre-exposure prophylaxis. Bookmark the permalink. ← Annie Lennox on HIV Activism The Ryan White Story (Continued) → […]

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: