Antiretrovirals for HIV prevention: when should they be recommended?

Abstract

Since the introduction of the first antiretroviral agent for HIV treatment, information on antiretroviral therapy (ART) effectiveness has grown continuously. In recent years, there has also been a growth of interest in use of ART for the prevention of HIV transmission, either by reducing the infectivity of the infected person or by protecting the uninfected individuals from HIV acquisition. The purpose of this review is to summarize the body of evidence available for treatment as prevention and pre-exposure prophylaxis and their effectiveness in prevention of infection. In addition, our aim is to discuss the operational aspects of both prevention strategies and to provide commentary for future HIV prevention programs.

Keywords::

• antiretroviral therapy
• HIV-1
• pre-exposure prophylaxis
• prevention
• treatment as prevention

Financial & competing interests disclosure

The authors would like to acknowledge funding to M Kiselinova from the ‘Special Research Grant – BOF grant’ of Ghent University (Grant no: 01N02712). L Vandekerckhove is supported by the Research Foundation – Flanders (FWO) (Grant no: 1.8.020.09.N.00). The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.

Key issues

• The constant increase of drug development efforts on improvement of combination antiretroviral therapy (cART) effectiveness and efficacy led to the development of simplified, well-tolerated, fixed-dose combinations that reduce HIV viral load to undetectable plasma levels.

• During past years, early administered cART is observed to significantly improve survival, lower the viral burden and viral diversity.

• There is evidence of widerange cART in prevention of onward transmission. The question arises as to whether the body of evidence is sufficient to motivate systematic early cART to prevent onward transmission?

• A wide range of effectiveness levels of treatment as prevention (TasP) has been observed in various studies. Suboptimal treatment and/or not sustained treatment adherence can lead to prevention failure from HIV transmission.

• Among the published studies, a wide variability in pre-exposure prophylaxis (PrEP) effectiveness has been observed as well, mainly dependent on treatment adherence. Suboptimal adherence decreases or even completely abolishes the effectiveness of PrEP.

• Increased sexual risk behaviors constitute a significant theoretical concern for TasP and PrEP use; thus, new bio-behavioral HIV interventions encompassing risk-reduction counseling, linkage to care and treatment, followed by provision of support are necessary.

• PrEP has been successfully implemented in serodiscordant couples, intravenous drug users and men who have sex with men. However, other most-at-risk populations like prisoners, internally displaced people, refugees etc., are under-represented in these prevention studies. These populations should be equally involved in the upcoming PrEP studies.

• More data are needed about combination prevention strategies, encompassing TasP or PrEP to achieve sustained decline in HIV transmission worldwide.

• Community and peer-driven prevention approaches based on a detailed investigation of the needs and specificities of specific subpopulations of HIV-infected individuals are critical for the efficient application of the HIV treatment and prevention guidelines.