Pre-Exposure Prophylaxis or PrEP

Pre-exposure prophylaxis (PrEP) involves putting HIV negative people on antiretroviral drugs (ARV) with the aim of protecting them from HIV infection. This blog looks at some of the pros and cons of PrEP.

Monday, October 24, 2011

Give Them Pills: Wealth, Health and Education Will Magically Follow

A major worry about PrEP is not that it won't work, nor even that it may result in increases in 'unsafe' sexual behavior, but that it simply ignores the conditions in which HIV is transmitted. It's is a process of giving people drugs but leaving them in the very circumstances in which they are thought to be at risk from infection with HIV and various other diseases.

If people engage in high levels of unsafe sex, PrEP may result in increases in such behavior; or it may reduce such behavior, though claims that it does are probably wishful thinking. But PrEP is not designed to influence behavior, it's designed to protect people from HIV transmission, even if they still engage in risky behavior. If it was feasible to influence people's sexual behavior, PrEP would not be necessary.

So it may reduce the 'risk' of a HIV negative person becoming infected. But it doesn't aim to reduce their risky behavior. The same applies to treating HIV positive people with antiretroviral drugs regardless of the clinical stage they have reached, known as 'treatment as (or 'is') prevention', 'test and treat', etc; this also doesn't reduce their risky behavior, nor that of their partners.

Surely, if people face risks as a result of their sexual behavior, it is their sexual behavior that needs to be influenced, not just their risk of infection with one or two diseases? And if their risks are not just sexual, if they also face risks from unsafe healthcare or unsafe cosmetic practices, surely those also need to be addressed?

Because, even if massive increases in the numbers of people on antiretroviral drugs result, either because of PrEP, treatment as prevention or any other scheme or combination of schemes the pharmaceutical industry dreams up, such risks are not acceptable. They would also be far more cheaply and efficiently addressed in their own right, rather than by using a scatter gun approach using drugs alone. Nature and other commentators appear to be concentrating on commercial risks, while ostensibly worrying about potential failure of PrEP to reduce HIV transmission.

Attempts to influence sexual behavior have been very unsuccessful, but what about the need to influence (antiretroviral) drug taking behaviors and various other measures to reduce risk, for example, by using PrEP or treatment as prevention strategies? If people are not highly compliant, the drugs won't work and may result in increased rates of resistance, which can be transmitted from person to person, as well as developing in individuals on ARVs.

This problem is particularly acute in resource poor settings, where HIV transmission rates may be highest. UNAIDS claim that 80-90% of HIV in African countries is transmitted through heterosexual sex. But they have never said what it is about heterosexual sex in a few African countries that could result in massive rates of transmission.

How could putting millions of people on drugs be a substitute for explaining why Africans face such huge risks when there is no evidence that people with HIV engage in, or have ever engaged in, types of sexual behavior that would greatly facilitate HIV transmission?

Where would PrEP come in? By doling out drugs to every HIV negative sexually active person? And treatment as prevention? By doling out drugs to every HIV positive sexually active person? African countries have not even come close to getting all HIV positive people who have reached a specific clinical stage of HIV progression on antiretroviral drugs, without which they will die. What magic is going to put half or more of the populations of some countries on drugs?

Also, enthusaists claim that PrEP, treatment as prevention and other strategies are not just about drugs, that people receive a whole range of benefits, such as regular testing, counselling and various other things. But this is not true. For most high prevalence countries, being on antiretroviral treatment doesn't even guarantee the supply of drugs. Several countries have run out of drugs, some on more than one occasion. But most people on drugs get little more than drugs.

Mitchell Warren, director of AVAC, a pharmaceutical front organization that aims to increase the use of HIV drugs, at all costs it seems, is quoted, as usual. He says "We think of PrEP as a pill, but we all recognize that PrEP is about a much broader programme". Recognizing this is not the same as providing a 'much broader program'. So far, those who receive the drugs are lucky to do so and those who can also feed themselves and get hold of other treatment needs are luckier still.

As for the necessity to test people at two to three month intervals, which country has succeeded in testing all sexually active people once, let alone once every two or three months, or even once a year? Countries with high HIV prevalence tend not to have the health service capacity to do any of the things AVAC and other pharmaceutical flag wavers glibly take for granted.

Another article asks "Will healthy uninfected people consistently take an expensive and powerful drug that can cause a range of side effects?" But that question seems to be of secondary importance compared to questions about ignoring the direct risks people face as a result of their sexual behavior and the state of health care and other services in their country. The question also ignores the problem of identifying exactly who could benefit from these strategies in high prevalence countries and how those most in need would be identified.

Apparently proponents of PrEP have said it would be "unethical" not to explore its potential. Perhaps so. But a prior concern would be establishing exactly what risks people in high prevalence countries face, rather than assuming that the risks are all sexual. Otherwise strategies like PrEP and treatment as prevention will only serve the interests of the pharmaceutical industry. That's probably all the industry wants, but recipients of these drugs might require a little more.


Tuesday, October 18, 2011

Do High HIV Prevalence Countries Have the Resources for Test and Treat?

When the 'treatment is (or as) prevention' (or 'test and treat' and various other names) hypothesis was first mooted, some wondered how it would work. The plan is to test everyone in a population for HIV regularly and treat everyone found to be infected immediately, rather than waiting for them to reach a particular clinical stage. Adherents of the strategy have vaguely suggested testing 80% or so of a population but this has not been achieved in any high prevalenc country. But if such levels of testing are achieved, how often would testing need to be carried out, and what would be the feasibility of testing such large numbers of people that often?

These issues are still fuzzy. But recent research suggests that many people are unaware of their HIV positive status, even where high rates of testing have been achieved. According to Salim Abdool Karim, this illustrates "the need for frequent repeat testing and comprehensive prevention efforts".

Whatever 'frequent' testing means in high resource, low HIV prevalence countries, it seems an unlikely option in high prevalence countries, which are all poor. Health services are generally not able to cope with relative simple health conditions and in many countries are simply too expensive to afford or too distant to reach. Karim's study shows that rates of new transmissions, which are unbelieveably high in parts of South Africa, are also high among those who tested negative only a short time before.

Getting everyone to test once for HIV, even where 'everyone' means 80%, is hard enough, but getting them to test every year would be a whole lot harder. And every year is not enough in the South African study area in question. So test and treat still raises more questions than answers; are there any high prevalence countries that can meet the challenge of testing so many people so frequently?


Wednesday, October 12, 2011

Resolved: We Must Stop Ignoring Bloodborne HIV in Africa

Why do so many HIV-positive children in Africa have HIV-negative mothers?For example, approximately 30% of HIV-positive kids aged 0-11 years have HIV-negative mothers in Mozambique (see pp. 177-181 in:
Why are so many virgin men and women found with HIV? In the Republic of Congo, for example, virgin women aged 15-49 years have higher HIV prevalence than all women, 4.2% vs 4.1% (see p. 101 in:

The personal stories behind these statistics are hard to fit with the common view that almost all infections are from sex. Why has there been so little attention and response to Africans with unexplained infections?

THE PURPOSE OF THIS NOTE IS TO INITIATE DEBATE ABOUT WHETHER TO CONTINUE TO IGNORE NON-SEXUAL HIV INFECTIONS IN AFRICA. To do so, this note presents four arguments for AIDS activists, both in Africa and elsewhere, to recognize and respond to HIV from skin-piercing procedures in African health care and cosmetic services.
1. DE-STIGMATIZING HIV/AIDS: Programs for HIV prevention in Africa – including especially foreign-funded programs -- focus almost exclusively on sex. With all attention on sex, the emotions, prejudices, and controversies around sex naturally spill over into HIV programs. Thus, it is not only wrong to think that all African HIV comes from sex (see points 3 and 4, below), but also confusing and distracting. Currently, stigma against HIV is so great that most people with unexplained infections keep silent, so as not to be accused of sexual behaviors that some people don’t like. When the public discourse is corrected to recognize blood-borne as well as sexual HIV (see:, people with HIV from blood risks will be able to speak out without facing stigma compounded by charges they are lying. And they will then be able to contribute to public efforts to make health care and cosmetic services safe.

2. PREVENTING HIV INFECTIONS: Ensuring that medical facilities are safe will not only prevent HIV infection but also the transmission of other blood borne pathogens. Across Africa, HIV prevalence is lower in countries where more people are aware of blood-borne risks for HIV; see:

3. SEX ALONE CAN’T EXPLAIN AFRICA’s HIV EPIDEMICS: All attempts to explain Africa’s epidemics as exclusively sexual have failed to find anything that is so different about sex in Africa that could account for Africa’s high rates of HIV prevalence. Studies find that Africans have fewer partners and use condoms more than Americans and Europeans.
Circumcision is less common in Europe than Africa. Sex can’t explain how HIV prevalence is lower after long term wars, and among people living further from health clinics. Sex is a risk for HIV because so many Africans are infected – but how are so many infected?  

4. EVIDENCE THAT AFRICANS GET HIV FROM SKIN-PIERCING EVENTS: A lot of evidence shows HIV transmission through skin-piercing procedures in Africa. Evidence is both old and new. For example:
(a) In 1985, Project SIDA in Kinshasa, Zaire (now the Democratic Republic of Congo), tested inpatient and outpatient children aged 1-24 months and their mothers for HIV. Seventeen (39%) of 44 HIV-positive children had HIV-negative mothers. Among children with HIV-negative mothers, “medical injections seemed to be the most important risk factor for HIV…” The study team noted, “Injections are often administered in dispensaries which reuse needles and syringes yet may not adequately sterilize them” (Mann et al, Risk factors for human immunodeficiency virus seropositivity among children 1-24 months old in Kinshasa, Zaire. Lancet 1986, ii: 654-7. p. 656.)
(b) Around 1990, WHO’s Global Programme on AIDS coordinated a study in Rwanda, Uganda, Tanzania, and Zambia to test in-patient children 6-59 months old and their mothers for HIV. Sixty-one (1.1%) of 5,593 children were HIV-positive with HIV-negative mothers; only three had been transfused. WHO experts concluded “the risk of non-perinatally acquired HIV and of patient-to-patient transmission of HIV among children in health care settings is low” (Global Programme on AIDS. 1992-1993 Progress Report. Geneva: WHO, 1993). A similar conclusion would be unthinkable if 1% of inpatient children in London, Boston, or Seoul were found with non-vertical HIV infections.
(c) A study among women in Malawi, 2003-05, found that women who had received hormone injections for birth control were 10.4 times more likely than other women to return with incident HIV infections, and 23 of 27 women with incident infections had received such injections; relative risk was adjusted for age, bacterial vaginosis, and number of sexual partners; reported condom use was uncommon for both women who acquired HIV infection (11.5%) as well as for those who remained HIV-negative (15.1%) (Kumwenda et al. Natural history and risk factors associated with early and established HIV type 1 infection among reproductive-age women in Malawi. Clin Infect Dis 2008; 46: 1913-1920).
(d) Many other studies in Africa link incident HIV to injections, report virgins with HIV, and report kids with HIV but HIV-negative mothers (see Chapters 7, 8, and 9 of Points to Consider, available for free download at:

PROPOSAL: Let’s dialogue about this at these websites –,,, – about the evidence, what to do, anything else relevant to the issue.

Simon Collery, David Gisselquist


Tuesday, October 4, 2011

Treatment As Prevention? Not By a Long Shot

There's an interview available with Myron Cohen on HIV treatment being a possible key to ending the pandemic. It would certainly be wonderful if existing drug therapies could reduce transmission enough for the pandemic to eventually be eradicated. Recent findings show that HIV positive people taking antiretroviral (ARV) drugs are less likely to transmit HIV to their partner. And there are good arguments for starting ARV treatment early, for the benefit of both the positive and the negative partner.

Frustratingly, the benefit of early treatment is highest for heterosexual couples. But the majority of HIV transmissions in the US are through male to male sex and intravenous drug use. However, the findings suggest that HIV treatment and transmission reduction is making a lot of progress in Western countries.

There is a somewhat different problem in African countries. Only a small percentage of HIV transmission is thought to come from intravenous drug use and men having sex with men, combined. And, according to UNAIDS, almost all HIV transmission is either through heterosexual contact or mother to child transmission.

It is clearly not feasible to put all people thought to be at risk of transmitting HIV on ARVs because the majority of them are not aware of their HIV status. And the stigma associated with HIV stems to a large extent from the view that it is almost always transmitted sexually. It means that every African, at least in high prevalence countries, is thought to be at risk, and mostly because of their sexual behavior.

Still, it would be interesting if UNAIDS were to rethink their attitude towards modes of HIV transmission, especially considering the orthodox view is not the result of any empirical investigations. Big Pharma could make a lot of money by persuading Western governments to use even more aid money to pay for drugs for HIV positive people. Global HIV policy would benefit from clarifying the relative contribution of various modes of transmission, sexual and non-sexual. Big money may work where the goal of reducing stigma, or even of implementing effective HIV prevention programs, hasn't.

The role of non-sexual modes of transmission, such as unsafe healthcare and cosmetic services, really needs to be questioned. Unless it is established how people are becoming infected, most prevention interventions will fail. Treatment may help with prevention, but it is not the same as prevention. It doesn't obviate the need to find ways of preventing HIV, however it happens to be transmitted.


Monday, October 3, 2011

Overall Benefits of PrEP as a Strategy Still Unclear

A trial comparing tenofovir microbicide with oral PrEP for HIV prevention is dropping the oral arm before the trial completion date. A monitoring board decided that it would not be possible to demonstrate any difference in effect between tenofovir PrEP and a placebo in preventing HIV infections. Other arms of the trial will continue.

Pharmaceutical industry front group AVAC's Warren Mitchell has expressed disappointment. But adverse publicity about PrEP is unlikely to be publicized as widely as the spin associated with favorable results, or results that can be dressed up as favorable. So far, it is the effectiveness of PrEP in preventing HIV transmission to women that is still in question. Women account for the majority of infections in young people in high prevalence African countries.

The HIV industry has still failed to show that PrEP, microbicide and various methods said to reduce HIV transmission do so in the specific case of sexual transmission. It is possible that drugs like Tenofovir also protect against non-sexual transmission, such as through unsafe healthcare and cosmetic services. But even if PrEP does protect against non-sexual transmission, it will not be the most appropriate strategy in these instances.

The best way to provide safe healthcare and cosmetic services is to ensure that strict hygiene and infection control procedures are followed, something the industry has long resisted. Separating any effect PrEP and microbicides may have on non-sexual transmission modes from its effects on sexual transmission modes would seem like a smart move. After all, there is little point in targeting populations who will not benefit from it; but nor is there much point in developing a strategy that is entirely inappropriate, even when that is where it may produce the best results.

The trials, the wishful thinking and the spin continue.