Days after US officials gave unprecedented approval for the use of an antiretroviral drug by HIV-negative people to reduce the risk of their acquiring the HI virus, the World Health Organization (WHO) has issued guidance to governments on so-called pre-exposure prophylaxis (PrEP).
WHO's guidelines, which call for a cautious and gradual roll-out, will likely see many countries begin to add PrEP to the growing arsenal of tools in the fight against HIV.
The guidance is based on evidence from clinical trials on the daily use of ARVs for HIV prevention among high-risk HIV-negative people. A 2010 study - Iniciativa Profilaxis Preexposicion, or Prexposure Prophylaxis Initiative (iPrEX) - among men who have sex with men (MSM) and transgender people, found that a daily dose of the ARV, Truvada - a combination of emtricitabine and tenofovir disoproxil fumarate - reduced HIV infection risk by about 42 percent.
The 2011 Partners PrEP study in Kenya and Uganda concluded that a daily dose of Truvada, taken by the HIV-negative partner in a heterosexual HIV-discordant relationship - where one sexual partner is infected and the other is not - could reduce the risk of HIV transmission by up to 75 percent.
However, WHO is careful in its advice, recommending that PrEP should be combined with the consistent use of condoms, as well as frequent HIV testing, counselling, and treatment of sexually transmitted infections. Noting that strict adherence to HIV medications - a requirement for the successful use of ARVs - was difficult for many people at high risk of HIV, the agency urged countries to start small in order to ascertain how best to deliver PrEP to "achieve the necessary adherence and maximum public health gains".
"Although the evidence of effectiveness is strong, it remains unclear how PrEP may best be implemented and scaled up in settings where its use might be most beneficial," the guidance states. "WHO is encouraging countries to undertake demonstration projects, and will offer advice on key questions and areas that could be addressed to facilitate understanding of the safety, effectiveness and sustainability of daily oral PrEP, and its use as an addition to existing HIV prevention efforts," WHO suggested.
"The outcome of these demonstration projects and country experience will also be used by WHO in three to five years' time to develop guidance for the implementation and scale-up of PrEP."
According to WHO, PrEP may be an additional intervention in countries where HIV transmission occurs among HIV-discordant couples, transgender women, and men who have sex with men. The agency has not reviewed the use of PrEP in other traditionally high-risk groups such as sex workers and injecting drug users.
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The guidance comes days after the United States Food and Drug Administration (FDA) announced its approval of Truvada for PrEP. The FDA recommended that HIV-negative individuals at high risk should take Truvada daily to lower their chances of becoming infected if they are exposed to the virus.
Kenyan government officials say the country is investigating the feasibility of adding PrEP to its repertoire of options. "Kenya is always receptive to new technologies to the extent that they are feasible, cost-effective and portend no adverse social, human rights or health system consequences," said Dr Peter Cherutich, acting head of Kenya's National AIDS and Sexually transmitted infections Control Programme (NASCOP).
"We have had extensive discussions on the matter [PrEP] and at the moment we are planning deliverability studies, beginning September 2012. If all goes well, we should adopt PrEP as part of combination prevention in mid-2013."
Cherutich said a number of factors would need to be taken into account before rolling out a new approach, including "competition with treatment, resource-wise, especially within a discordant relationship in which the infected partner may be preferred to receive treatment, rather than the uninfected partner receiving PrEP", the potential for incorrect of ARVs for prevention, concerns about reinforcing complacency over HIV, and the cost of funding such a programme.
James Kamau, the coordinator of Kenya Treatment Access Movement, said the addition of treatment to the prevention "toolkit" was welcome. "Countries like Kenya must now change their policies to include Truvada as a critical component of their HIV prevention strategy," he told IRIN/PlusNews. "We have so many people in need of antiretroviral treatment who aren't getting it, and we must embrace anything that would stop that number from increasing."
He said PrEP would require adequate sensitization to prevent people from abandoning cheaper, widely available, tried-and-tested HIV prevention methods like condom use.
Representatives of some "most-at-risk" groups expressed concern that they would not benefit from PrEP. "The stigma and taboo attached to same-sex activity means many men who have sex with men, and women who have sex with women, are not able to easily access health services," said Denis Nzioka, editor of Identity Magazine.
"The government would need to ensure that the message [reaches] all groups who need to have access to it, and. that these groups are fully aware that Truvada works in conjunction with other HIV prevention methods such as condoms, water-based lubricant and so on," he said.
"Fighting HIV is not just a health issue, it is also a human rights issue - decriminalization of same-sex activity will be key to sexual minorities accessing crucial health services."
Uganda's Ministry of Health appears concerned with the cost of PrEP and the danger of complacency. "Usually, we change our HIV prevention and treatment policy after thorough scientific research and technical assessments. We have also to look at whether it's affordable and conforms to our disease pattern. We don't see any reason to change at the moment - the regimens we currently have in the country are working," Christine Ondoa, Uganda's Health Minister, told IRIN/PlusNews.
Photo: Natalie Bailey/IRIN
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"Truvada is good," said Asuman lukwago, the permanent secretary in the Ministry of Health. "However, the medicine is too expensive - encouraging [the use of] it will increase our prevention and treatment burden. We currently have problems with the Global Fund [to Fight AIDS, Tuberculosis and Malaria] money, which we rely on so much."
The manufacturer of the approved pill estimates that the medicine will typically cost US$13,900 per person per year in the US.
He suggested that "We should continue using cheaper protection methods like condoms. Truvada is not a vaccine for HIV, it's a preventive drug - people should stick to the ABC [abstinence, be faithful, and correct and consistent use of condoms.]"
But activists say the government should look into the official use of PrEP as part of the package of options, especially as HIV prevalence in Uganda has climbed from 6.4 percent to 7.3 percent in the last five years.
"The government knows the infection rates have gone up... it should focus on prevention measures to protect people. The use of Truvada for pre-exposure prophylaxis is one of [them]," said Florence Buluba, the executive director of the National Community of Women Living with AIDS (NACWOLA). "The Ministry of Health should do whatever it takes to ensure all Ugandans stay healthy."