Giuseppe
Emeritus
HIV, transmitted drug resistance, and the paradox of preexposure prophylaxis (Proc Natl Acad Sci USA, abstract, edited)
[Source: PNAS, <cite cite="http://www.pnas.org/content/107/27/12381.short?rss=1">HIV, transmitted drug resistance, and the paradox of preexposure prophylaxis ? PNAS</cite>. Abstract, edited.]
HIV, transmitted drug resistance, and the paradox of preexposure prophylaxis
Virginie Supervie a, J. Gerardo Garc?a-Lerma b, Walid Heneine b, and Sally Blower a,
Author Affiliations: a) Center for Biomedical Modeling, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California, Los Angeles, CA 90024; and b) Laboratory Branch, Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, Atlanta, GA 30329
*Present address: INSERM U943 Paris and UPMC Universit? Paris 6, UMR S943, F75013, France.
Edited* by Simon A. Levin, Princeton University, Princeton, NJ, and approved May 25, 2010 (received for review May 4, 2010)
Abstract
The administration of antiretrovirals before HIV exposure to prevent infection (i.e., preexposure prophylaxis; PrEP) is under evaluation in clinical trials. Because PrEP is based on antiretrovirals, there is considerable concern that it could substantially increase transmitted resistance, particularly in resource-rich countries. Here we use a mathematical model to predict the effect of PrEP interventions on the HIV epidemic in the men-who-have-sex-with-men community in San Francisco. The model is calibrated using Monte Carlo filtering and analyzed by constructing nonlinear response hypersurfaces. We predict PrEP interventions could substantially reduce transmission but significantly increase the proportion of new infections caused by resistant strains. Two mechanisms can cause this increase. If risk compensation occurs, the proportion increases due to increasing transmission of resistant strains and decreasing transmission of wild-type strains. If risk behavior remains stable, the increase occurs because of reduced transmission of resistant strains coupled with an even greater reduction in transmission of wild-type strains. We define this as the paradox of PrEP (i.e., resistance appears to be increasing, but is actually decreasing). We determine this paradox is likely to occur if the efficacy of PrEP regimens against wild-type strains is greater than 30% and the relative efficacy against resistant strains is greater than 0.2 but less than the efficacy against wild-type. Our modeling shows, if risk behavior increases, that it is a valid concern that PrEP could significantly increase transmitted resistance. However, if risk behavior remains stable, we find the concern is unfounded and PrEP interventions are likely to decrease transmitted resistance.
* mathematical model * men who have sex with men * prevention * epidemics * antiretrovirals
Footnotes
To whom correspondence should be addressed. E-mail: sblower@mednet.ucla.edu.
Author contributions: V.S. and S.B. designed research; V.S. contributed new reagents/analytic tools; and V.S., J.G.G.-L., W.H., and S.B. performed research, analyzed data, and wrote the paper.
The authors declare no conflict of interest.
This Direct Submission article had a prearranged editor.
This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1006061107/-/DCSupplemental.
Freely available online through the PNAS open access option.
-
-----
[Source: PNAS, <cite cite="http://www.pnas.org/content/107/27/12381.short?rss=1">HIV, transmitted drug resistance, and the paradox of preexposure prophylaxis ? PNAS</cite>. Abstract, edited.]
HIV, transmitted drug resistance, and the paradox of preexposure prophylaxis
Virginie Supervie a, J. Gerardo Garc?a-Lerma b, Walid Heneine b, and Sally Blower a,
Author Affiliations: a) Center for Biomedical Modeling, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California, Los Angeles, CA 90024; and b) Laboratory Branch, Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, Atlanta, GA 30329
*Present address: INSERM U943 Paris and UPMC Universit? Paris 6, UMR S943, F75013, France.
Edited* by Simon A. Levin, Princeton University, Princeton, NJ, and approved May 25, 2010 (received for review May 4, 2010)
Abstract
The administration of antiretrovirals before HIV exposure to prevent infection (i.e., preexposure prophylaxis; PrEP) is under evaluation in clinical trials. Because PrEP is based on antiretrovirals, there is considerable concern that it could substantially increase transmitted resistance, particularly in resource-rich countries. Here we use a mathematical model to predict the effect of PrEP interventions on the HIV epidemic in the men-who-have-sex-with-men community in San Francisco. The model is calibrated using Monte Carlo filtering and analyzed by constructing nonlinear response hypersurfaces. We predict PrEP interventions could substantially reduce transmission but significantly increase the proportion of new infections caused by resistant strains. Two mechanisms can cause this increase. If risk compensation occurs, the proportion increases due to increasing transmission of resistant strains and decreasing transmission of wild-type strains. If risk behavior remains stable, the increase occurs because of reduced transmission of resistant strains coupled with an even greater reduction in transmission of wild-type strains. We define this as the paradox of PrEP (i.e., resistance appears to be increasing, but is actually decreasing). We determine this paradox is likely to occur if the efficacy of PrEP regimens against wild-type strains is greater than 30% and the relative efficacy against resistant strains is greater than 0.2 but less than the efficacy against wild-type. Our modeling shows, if risk behavior increases, that it is a valid concern that PrEP could significantly increase transmitted resistance. However, if risk behavior remains stable, we find the concern is unfounded and PrEP interventions are likely to decrease transmitted resistance.
* mathematical model * men who have sex with men * prevention * epidemics * antiretrovirals
Footnotes
To whom correspondence should be addressed. E-mail: sblower@mednet.ucla.edu.
Author contributions: V.S. and S.B. designed research; V.S. contributed new reagents/analytic tools; and V.S., J.G.G.-L., W.H., and S.B. performed research, analyzed data, and wrote the paper.
The authors declare no conflict of interest.
This Direct Submission article had a prearranged editor.
This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1006061107/-/DCSupplemental.
Freely available online through the PNAS open access option.
-
-----