Melbourne, Australia - A new international study, which was also carried out in Cape Town, has revealed that taking antiretrovirals as a preventative measure is not only safe, but can fully protect those at high risk of HIV infection from contracting the disease.
The iPrEx Open Label Extention (Ole) study, which was presented at the 20th International Aids Conference in Melbourne and published in the Lancet, showed that even if individuals missed some of their daily doses, the pill which contains two ARVs – tenofovir and emtricitabine – still provided a high degree of protection against HIV infection. The findings are expected to debunk suggestions that HIV pre-exposure prophylaxis (PrEP) may be unsafe.
While the effectiveness of PrEP was first proven in 2010, there had been some concern that it might not be safe to use long term. There was also speculation that access to PrEP could either cause individuals to increase risky sexual behaviour or be reluctant to use it.
But the latest study found no evidence of “risk compensation”.
It also found that there was an interest and willingness to use the preventative method by those at high risk of HIV-infection.
Tested on more than 1 600 HIV-negative men, including gay men, bisexuals, transgender women and men-sleeping-with men (MSM) at 11 research sites on four different continents, the latest study found that PrEP provided 100 percent protection among participants who took the pill four times or more every week.
Those who took the pill two or three times a week registered a protection rate of about 84 percent. Those who took fewer than two tablets in the same period had no protection at all.
Carried out by the US-based National Institute of Health over an 18-month period in Chicago, San Fransisco, Boston, Thailand, Rio de Janeiro and Cape Town, among other sites, researchers are convinced that using pre-exposure prophylaxis could save lives of high-risk populations.
Gay men are regarded as the key population or at highest risk of HIV infection and transmission. At the conference it also emerged that while the HIV/Aids burden was declining in parts of the world, HIV infection among gay men was increasing.
Professor Olive Shisana, of the Human Science Research Council, said because of the stigma and discrimination attached to gay men, often these men were reluctant to seek care for their sexual health from clinics and hospitals.
Lead researcher of the study, Robert Grant from the Gladstone Institute, University of California, said the latest research on use of ARVs as prevention, was important, especially given the emerging guidelines recommending expanded use of PrEp.
The guidelines also required that patients receive an HIV-test and confirm negative status before starting PrEP.
“The project provides critical insight into what happens as PrEP transitions from clinical trials to clinical practice. It is particularly compelling to see such strong interest in PrEp among young gay and bisexual men who are increasingly impacted by HIV,” he said.