It’s difficult to get patients to take a long-term medication as directed, even if it could prevent a disease as deadly as AIDS.
That’s one of the conclusions researchers reached following a large clinical trial among African women. The trial was supposed to determine whether prescribed tablets or a gel could be used to prevent HIV.
Instead, the study revealed that many of the more than 5,000 women who took part did not use the medication, even though they reported doing so.
The Vaginal and Oral Interventions to Control the Epidemic (VOICE) study, led by Dr. Jeanne M. Marrazzo of the University of Washington, was published last week in The New England Journal of Medicine.
Three months into the study, blood tests indicated most participants were not using their assigned product of either tenofovir (Viread) or Truvada tablets or a vaginal tenofovir gel.
The overall results showed that both interventions were ineffective. However, among women in the gel group whose blood tests showed they were using the gel, HIV risk appeared to be significantly reduced, the authors concluded.
To some, the VOICE study may seem like a disappointing setback for HIV prevention. There are already concerns about inconsistent compliance with the FDA-approved daily oral regimen of Truvada for pre-exposure prophylaxis (PrEP).
Not necessarily, say HIV and infectious disease doctors.
Dr. Amesh Adalja of the University of Pittsburgh Medical Center for Health Security told Healthline it’s important to remember that even though studies are conducted among population groups, the drugs are prescribed to individuals.
“Despite the recent failure of the VOICE PrEP trial to show benefit, extrapolating those results to all contexts and to all individuals isn’t warranted,” Adalja said. “If an individual requests PrEP and is compliant, he or she will benefit.”
In the case of the African study, it was stigma — not science — that caused it to flop, doctors say.
In an editorial accompanying the research Dr. Michael Saag explains that the authors later learned the women didn’t take their medication because they didn’t want people to think they had HIV. They also feared that the medication was so powerful it could be dangerous to those not infected with the virus.
In his editorial, Saag concludes: “Much more work is needed, not so much in the realm of understanding the biological basis of pre-exposure prophylaxis as a preventive treatment but rather the realm of understanding behavioral barriers in the setting of strong social stigma.”
It’s Too Early to Give up on PrEP
A person can’t be forced to protect themselves against HIV and other STDs. But Dr. Susan Cu-Uvin a professor of gynecology at Brown University, told Healthline the chances of adherence are better when people have a variety of prevention methods to choose from.
“People want one magic bullet. That’s the problem,” Cu-Uvin said. “What works in South Africa will not work in Boston. What works in New York won’t work in the Ivory Coast. We are all wanting a ‘one size fits all’ when we need to do our homework.”
The VOICE study cost $94 million, according to a story published in The New York Times. It was funded by the National Institutes of Health (NIH).
“We spend a lot of money on the science, but I don’t know that we spent the same amount of time or money understanding these women and their thinking,” Cu-Uvin said. “… understanding these women and asking them what they would like, what they would not like, and why they would be motivated to use the gel and the tablet.”
Dr. Philip Chan, also a professor at Brown University, deals with PrEP at clinics in Providence, Rhode Island and Jackson, Mississippi. He said many people still do not know about PrEP but “the word is getting out and it’s starting to ramp up exponentially. People are coming to me now and saying ‘I heard about this on the news.’”
Cu-Uvin concurred. “It will take time and no one wants to believe that.”
Other HIV prevention specialists have echoed these sentiments, noting it took a long time for Americans to embrace the birth control pill.
Tackling the Compliance Problem
HIV prevention measures continue to be examined on both the scientific and behavioral levels.
Perhaps the most promising scientific work right now is being conducted by Dr. David Ho of the Aaron Diamond AIDS Research Center.
Ho has seen promising results using long-lasting injections in macaque monkeys. He said a shot given once every one to three months for protection against HIV could improve HIV prevention by leaps and bounds.
“The compliance issue is something that may become less of a concern as longer acting antiretroviral approaches are developed,” Adalja said.
Cu-Uvin said it’s going to take time to come up with prevention measures that work for everyone.
“Somewhere along the line we’re all getting it right a bit at a time. Everybody is studying every piece of it,” she said.
“The HIV prevention field is still developing and moving forward. I think at some point we will realize that PrEP may be a viable alternative to condoms,” he said.