Research findings underscore need for additional HIV prevention options for women

Moses Wasamu, Kenya
Results of recent research findings underscore the need to accelerate development of additional HIV prevention options for women in the area of HIV prevention. The HIV prevention trial was done among women in Uganda, Zimbabwe and South Africa, and its results released at a scientific conference in the US early March. At the same time, the results from a large-scale HIV prevention trial among African women known as VOICE (Vaginal and Oral Interventions to Control the Epidemic), provide an urgent reminder that products must meet the needs of the people using them.

“The high rates of new HIV infections among women, especially young women, are the most shocking and disturbing data from this trial. They are a sobering reminder of how desperately women need new prevention options that they can and will use to protect themselves from HIV,” said Elizabeth Bukusi, Deputy Director of the Kenya Medical Research Institute (KEMRI) and an AVAC Board Member.

“The VOICE results teach us again that an urgent need for new prevention options does not mean women will automatically demand or use those products.” AVAC, a global non-profit organization that advocates for HIV prevention says that while disappointing, the results lend new urgency and direction to the search for additional safe and effective HIV prevention options for women. Researchers announced that none of the three pre-exposure prophylaxis (PrEP) and microbicide interventions tested in VOICE – daily oral tenofovir, daily oral TDF/FTC (Truvada), and daily 1% vaginal tenofovir gel – provided additional protection against HIV in the study, likely because few of the women in the trial used the products as directed.

This low adherence explains the lack of benefit and is consistent with data from other antiretroviral (ARV)-based prevention trials that found a correlation between higher levels of adherence and protection from HIV. The new results were presented in Atlanta at the 20th Conference on Retroviruses and Opportunistic Infections (CROI). “The VOICE results reinforce what we already know from previous trials - these interventions work when they are used, and they don’t work when they are not used,” said Mitchell Warren, AVAC Executive Director. “PrEP is still a valuable option for many women, and men, who recognize their risk and can take PrEP consistently. Now we have a dual responsibility to understand who might benefit from daily PrEP and ensure that they can access it, and to accelerate the development of additional options that can meet the urgent needs of others.” PrEP is short for Pre-Exposure Prophylaxis. It is a new HIV prevention method in which people who do not have HIV, take a daily pill to reduce their risk of becoming infected. When used consistently, PrEP has been shown to be effective in men who have sex with men (MSM) and heterosexually-active men and women. Dr.Nelly Mugo, who has worked on a number of HIV prevention trials, including the Partners PrEP trial in Kenya, says that 4 clinical trial PrEP sites in Kenya - Kisumu (KEMRI); Nairobi (University of Nairobi), Thika (Kenyatta National Hospital); Eldoret (Moi Teaching and Referral Hospital) - did studies and the findings were reported at the International AIDS conference in Rome 2011.
“PrEP using Truvada has been shown to effectively prevent 75% of HIV infections and when used correctly, this goes up to 90% in clinical trial studies,” says Dr. Mugo.
Dr. Mugo adds that the Thika and Kisumu sites are currently conducting demonstration projects to determine the acceptability of PrEP at community level outside clinical trial setting. Whereas there may be individual providers prescribing PrEP, she says that the ministry of health has not yet added this strategy to the HIV prevention tools that it supports. A range of trials has shown varying levels of effectiveness of tenofovir-based prevention for heterosexual men and women, and for men and transgender women who have sex with men. The VOICE data do not invalidate the prior trial results, including the finding that daily oral tenofovir-based PrEP provided high levels of protection for women in stable relationships where one partner was HIV-positive, and that 1% vaginal tenofovir gel was modestly effective on a different dosing schedule.

“Previous trials of tenofovir-based gel and pills have shown that biologically this approach can work, but only if the product is used. HIV prevention is never just biomedical – behavior is key. What we’ve learned from VOICE and other trials is that adherence to the prescribed dose – the behavioral component – is the variable that determines effectiveness,” Warren added. VOICE showed a very high incidence of HIV in the trial - 5.7 percent among all the women in the trial and 8.8 percent among unmarried women under the age of 25 in South Africa. The VOICE findings are closer to what the Kenya AIDS Indicator Survey (KAIS) report of 2007 found out; that women were more likely to be HIV-infected (8.4%) than men (5.4%), and that young women were 4 times more likely to be infected than boys their age. In other words, 3 out of 5 HIV-infected Kenyans are female. Research has found out that women and girls are more susceptible than men and boys to infection from HIV due to biological factors and gender norms, among other reasons.

“These women are at such high risk for HIV, we owe it to them to work with them to find the options that they can and will use to protect themselves,” Warren said. Experts say that for some individuals at high risk for HIV infection, PrEP may represent a much-needed additional prevention method, but it will not be right for everyone and is not intended to be used in isolation, but rather in combination with other methods to reduce the risk of getting HIV infection. The US Centre for Disease Control and Prevention (CDC), which has been working with Kenyan scientists in KEMRI for many years, is currently working to ensure safe and effective PrEP use and to address key questions about acceptability, access, adherence, behavioral risks, and patient outcomes in community settings. Warren says that the VOICE results underscore that it is time to put more effort in the behavioral side of new HIV prevention options.

“First, it means figuring out how to identify those who are most likely to use and benefit from PrEP and other emerging options. We know daily PrEP can make a potentially life-saving difference for many women and men at risk for HIV right now, and we have a responsibility to reach them with new methods and with the support they need to use them,” she says. She says that there is need to redouble research into additional options that women can control, want and use. Also, several promising approaches are already being studied, including vaginal rings and injections that may only need to be administered every month or quarter, as well as less-than-daily dosing schedules of pills or gels, which may be preferable to some. “In addition, research and development resources are urgently needed for combined contraceptive and HIV prevention methods, which would address many women's needs more comprehensively. Similarly, research to find HIV vaccines, which would overcome many of the issues around adherence, also needs an aggressive push,” says Warren.

Moses Wasamu, Kenya
Citizen News Service - CNS 
March 2013