The level of caution (and even hostility) from many healthcare workers in the UK to using PrEP to prevent HIV transmission, appears to actually increase in proportion to the evidence that supports its potential benefit.
The practical and medical concerns relating to cost, resistance, toxicity, adherence and prescription details are all important, but when potential protection is now predicted as >99% in people who take 4-7 daily doses a week, it becomes essential that this option be available for high risk individuals, given the current statistics on continued new infections.
A study presented by the UK Health Protection Agency suggested that while PrEP may not be for everyone -- a fear of those most skeptical -- a significant proportion of high risk gay men see PrEP as an option they would actively choose.
The Gay Men's Sexual Health Survey is a biennial community based cross sectional survey that in 2011 (from March to June) recruited more than 1200 gay men from social venues (bars, nightclubs and saunas) in London. The questionnaires were self-completed anonymously and 1005 participants also agreed to a saliva sample for HIV testing (anonymised soley for the survey).
In addition to sexual health and behaviour, the survey asked about prior use of PEP and PrEP and "How likely is it that you would take a pill (oral dose) on a daily basis to prevent HIV infection?"
Of the 768/842 HIV negative men who answered this part of the survey, 34% reported interest in PrEP as "very likely" and 16% as "likely". Just as importantly, 15% were "unlikely" and 26% "very unlikely". The important conclusion is that while some men would not want to take PrEP at least as many (twIce as many in this survey) would find a daily oral prophylactic pill acceptable.
Demographics of the 842 men who were HIV negative included mean age 34 years (SD +/- 9.2; range 18-71 years), 82% were white, 86% employed, 93% >2 years education post 16 years and 78% had an inner London postcode. While 10% had previously used PEP, only 2% had used PrEP.
In multivariate analysis, the predictors for wanting to use PrEP (adjOR, 95%CI) included younger age (<35 years: aOR 1.58; 1.16-2.15), recent attendance of STI clinic (aOR 1.59; 1.03-2.46) and previous use of PEP (aOR 1.96; 1.17-3.26). Having >10 partners in the last year, unprotected anal intercourse (UAI) in the last year, or UAI with unknown status partner in the last year were statistically significant factors only in the unadjusted analysis. However, younger age (aOR 2.29; 1,68-3.13) and >10 partners (aOR 2.47; 1.76-3.48) were both strongly associated with STI attendance in the last year.
A second study on acceptability of PrEP, from a smaller survey of gay men attending Manchester Centre for Sexual Health, was presented by Thng and colleagues as a poster.2
Of over 3000 attendees from November 2011 to January 2012, 12% were gay men, with 95/112 men who agreed to the survey completing and returning it. The mean age was 28 years, 80% were white Caucasian, with a median of 4 sexual partners in the previous year. 84% said that they used condoms "at least 50% of the time" and staying HIV negative was important to 87%.
Willingness to use oral PrEP was reported by 64% with more than half of these replies indicating use of daily PrEP for >6 months, 90% that monitoring would be acceptable and 85% that information provided on the potential side affects also sounded acceptable.
Approximately 20% of people interested in PrEP were only interested if it could be taken around or after sex, rather than daily. 66% said that taking PrEP would not change the frequency of condom use and none said that they would stop condom use altogether. Most (86%) would be unlikely to have more partners.
The emphasis on background risk is important. The most impressive data has come from the iPrEX study that enrolled generally young gay men who had multiple aspects of their lives that put them at high risk. This included young men, mutilple partners, high alcohol and recreational drug use, low condom use, rare discussion about HIV prior to sex, high levels of transactional sex, etc.3
PrEP is unlikely to be affordable for most people unless this is covered by public healthcare. At current therapeutic prices, daily Truvada is likely to cost several thousand pounds a year, even with intermittent dosing (the efficacy of which has yet to be established).
The option for this intervention has the potential for a young gay man to have a higher protection than any other intervention, for what might be a short period of an otherwise long and healthy life. Last year more than 3000 gay men in the UK were diagnosed HIV positive and another HPA presentation at BHIVA highlighted than 22% of these were recent infections. When looking at the impact of age, recent infections were disproportionally higher (30%) for gay men under 25 (compared to 15% for those older than 50 years).4
This survey is an important first step in clearly demonstrating a high level of interest from the target group for who this intervention is likely to be appropriate and cost effective.
While this was a survey in broadly a white, educated and economically stable population, the survey was also conducted when information about the efficacy of PrEP was relatively new, and prior to the most recent efficacy data.
It also shows that it might be relatively easy to identify men at higher risk though GUM clinics and this might also broader the demographics of people at risk, given the more recent data from CROI this year supporting higher efficacy.5
It now becomes a public health issue, that should be promptly recognised, both for research and service provision. It is difficult to understand why the PROUD study for PrEP in high risk gay men was turned down for NIHR funding. However, a smaller pilot study, sponsored by Gilead, still hopes to enrol 500 higher risk gay men later this year using a design that includes deferred (by 6 months) vs. immediate PrEP.
- Aghaizu A et al. Who would use PrEP? Predictors of use among MSM in London. 18th BHIVA Conference, 18-20 April 2012. Oral abstract O23.
- Thng C et al. Acceptability of HIV pre-exposure prophylaxis (PrEP) and associated risk compensation in men who have sex with men (MSM) accessing GU services. 18th BHIVA Conference, 18-20 April 2012, Birmingham. Poster abstract P233.
- Grant RM et al. Preexposure chemoprophylaxis for HIV prevention in men who have sex with men. NEJM. 23 November 2010 (10.1056/NEJMoa1011205). Free access.
- Aghaizu A et al. Recently acquired HIV infections: an overview of surveillance in the UK. 18th BHIVA Conference, 18-20 April 2012, Birmingham. Oral abstract O19.
- Anderson P et al. Intracellular tenofovir-DP concentrations associated with PrEP efficacy in MSM from iPrEx. 19th CROI 2012, Seattle. Oral late breaker abstract 31LB.
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