Attempting to prevent HIV infection via vaginal gels or daily medicine has proven to be ineffective in the southern African region that is devastated by a high number of cases of the disease, because people did not use the medicine as required.

The finding came from a large-scale HIV prevention trial among African women known as VOICE (Vaginal and Oral Intervention to Control the Epidemic) and has provided an urgent reminder that products must meet the needs of those people using them.

While the results are disappointing, they emphasize the need for additional safe and effective HIV prevention options for women.

In 2010, a groundbreaking study provided evidence that vaginal gel containing antiretroviral (ARV) drug tenofovir could greatly decrease HIV infections in women who used it before and after sex, offering the possibility of preventing disease transmission by giving it to women to use as protection.

In the current study, testing of the gel and two types of related pills among 5,000 women in Zimbabwe, Uganda, and South Africa revealed that more than 70 percent of these women did not use their medication. The researchers collected blood samples from all participants.

Jeanne Marrazzo, a researcher on the project for the University of Washington said:

“We are obviously disappointed in the results. We were very hopeful that these products, which we know have been effective in other studies and clearly have a lot of promise, would work.”

East and southern Africa are the parts of the world most affected by the HIV epidemic. Among those living around the world with HIV, 34 percent lived in 10 countries of southern Africa in 2009, according to the U.N. Program on HIV/AIDS.

Researchers have been exploring options for an inexpensive, safe, and simple medication to reduce the risk of AIDS transmission for a low income population with little access to quality health care.

Yesterday, investigators in this latest study announced that none of three pre-exposure prophylaxis (PrEP) and microbicide interventions – daily oral tenofovir, daily oral TDF/FTC (Truvada) and daily 1% vaginal tenofovir gel – gave extra protection against HIV.

The low rate of adherence explains the lack of benefit and is in line with data from other antiretroviral-based prevention trials that found a link between high levels of adherence and protection from HIV.

The study also found that the group most likely to contract HIV – unmarried women under 25 – was also the least compliant with drug regimens.

Previous trials of tenofovir-based gel and pills have shown that this approach can work, however only if the product is used. HIV prevention is not just biological but also dependent on the behavior of these women and girls. Put simply, good adherence is required.

Marrazzo commented:

“We need to rethink the design of these intervention trials that are being done in healthy people because it is difficult for anybody to take a pill or anything every day, particularly when you are healthy and do not feel that you need a drug.”

The organizations involved in this study call for further research in the development of additional HIV prevention options that are less dependent on adherence.

These options could include different delivery methods, including:

  • long-acting rings
  • injections
  • dosing schedules of longer intervals than once every 24 hours

Written by Kelly Fitzgerald