Editorial Commentary: HIV Chemoprophylaxis for Adolescents: Educable Moment, Not Magic Bullet

Abstract

The shape of the human immunodeficiency virus (HIV) epidemic is becoming bimodal because of increasing incidence among young people and the aging of persons infected long ago who are living longer because of access to highly active antiretroviral therapy (HAART) [1–3]. Globally, almost onehalf of new HIV infections are occurring among adolescents, and in the United States, the subpopulation with the greatest recent increase in HIV infections is youth from racial and ethnic minority communities [1–5]. A recent 6-city study of black men who have sex with men found that annualized HIV incidence approached 6% among men aged 25% of the seroconversions were not associated with primary partners [15]. In populations where HIV remains highly stigmatized and serostatus disclosure remains uncommon, relying on treatment as prevention to stop the spread of HIV in young people may expose high-risk youths to unnecessary levels of risk. In less than 3 years the efficacy of antiviral chemoprophylaxis, also known as preexposure prophylaxis (PrEP), has been demonstrated in trials involving heterosexual HIV-discordant couples [16], young women [17, 18], and heterosexual and homosexual men [19, 20]. The effect sizes of the protective benefit have varied and some of the studies did not demonstrate efficacy. Although medication adherence (as measured by serum drug levels in the blood and genital tract) appears to play a pivotal role in whether trials demonstrated PrEP efficacy [20, 21], other factors, such as tissue pharmacology and host mucosal responses, deserve further careful evaluation. Moreover, now that there is proof of concept for the use of oral, daily PrEP with tenofovir and emtricitabine, new studies are under way to determine whether more parsimonious dosing (because many individuals may not be engaging in risk every day), different drugs (to minimize the risk of crossresistance and to avoid some toxicities), and different delivery systems (eg, modalities that are less dependent on adherence such as intravaginal rings or periodic injections) may obviate some of the concerns raised in the earlier studies. Therefore, given some of these uncertainties about the optimal way to use chemoprophylaxis, should PrEP implementation be delayed for adolescents? In an article in this issue of Clinical Infectious Diseases, Pace et al discuss why PrEP may offer new opportunities to prevent HIV spread among a new generation of young people, while discussing the challenges to optimal implementation [22]. Given the rates of new HIV infections in some subpopulations, the addition of any proven prevention Received 17 November 2012; accepted 29 November 2012. Correspondence: Kenneth Mayer, MD, Fenway Health, 1340 Boylston St, Boston, MA 02215 (kmayer@ fenwayhealth.org). Clinical Infectious Diseases © The Author 2012. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals. permissions@oup.com. DOI: 10.1093/cid/cis1026