The efficacy of HIV pre-exposure prophylaxis (PrEP) relies on adherence and may also depend on the route of HIV acquisition. Clinical studies of systemic tenofovir disoproxil fumarate (TDF) PrEP revealed reduced efficacy in women compared to men with similar degrees of adherence. To select the most effective PrEP strategies, preclinical studies are critically needed to establish correlations be...

We investigate how SAT coaching (also known as “SAT Prep”) affects the value of the SAT as an evaluative tool, vis-á-vis other applicant signals such as high school transcript and letters of recommendation. Theoretically, we develop a simple “meritocratic” model of selective college admission that illustrates how SAT Prep may alter the emphasis a college places on SAT scores, depending on perce...

INTRODUCTION Despite the efficacy of pre-exposure prophylaxis (PrEP) in preventing HIV transmission, few studies have evaluated PrEP use and retention in care outcomes in real-world settings outside of clinical trials. METHODS Data were collected from PrEP clinical care programmes in three mid-size US cities: Providence, Rhode Island (RI); Jackson, Mississippi (MS); and St. Louis, Missouri (M...

PURPOSE OF REVIEW We discuss selected statistical issues in the design and analysis of preexposure prophylaxis (PrEP) trials. The general principles may inform thinking for other interventions in HIV prevention. RECENT FINDINGS To date, four different designs have been used to determine the effectiveness of PrEP: randomized, double-blind, placebo-controlled; randomized, open-label, immediate ...

While HIV-1 continues to spread, the use of antivirals in preexposure prophylaxis (PrEP) has recently been suggested. Here we present a modular systems pharmacology modeling pipeline, predicting PrEP efficacy of nucleotide reverse transcriptase inhibitors (NRTIs) at the scale of reverse transcription, target-cell, and systemic infection and after repeated viral exposures, akin to clinical trial...

INTRODUCTION Despite progress in scaling up antiretroviral treatment, HIV prevention strategies have not been successful in significantly curbing HIV incidence in Latin America. HIV prevention interventions need to be expanded to target the most affected key populations with a combination approach, including new high impact technologies. Oral pre-exposure prophylaxis (PrEP) is recommended as ad...

Background. Once daily tenofovir/emtricitabine-based pre-exposure prophylaxis (PrEP) can reduce HIV acquisition in men-who-have-sex-with-men (MSM). To inform large-scale PrEP implementation, we examined the potential population-level impact and cost-effectiveness of different PrEP implementation strategies. Methods. We developed a dynamic, stochastic compartmental model of HIV transmission amon...

INTRODUCTION The Amsterdam PrEP project is a prospective, open-label demonstration study at a large sexually transmitted infection (STI) clinic. We examined the uptake of PrEP; the baseline characteristics of men who have sex with men (MSM) and transgender persons initiating PrEP; their choices of daily versus event-driven PrEP and the determinants of these choices. METHODS From August 2015 t...

OBJECTIVE In France, indications for pre-exposure prophylaxis (PrEP) for HIV prevention are based on individual-level risk factors for HIV infection. However, the risk of HIV infection may also depend on characteristics of sexual partnerships. Here we study how place-based selection of partners change transmission and the overall efficiency of PrEP. METHODS We used the PREVAGAY survey of sexu...

PURPOSE OF REVIEW The WHO recommends preexposure prophylaxis (PrEP) in populations at substantial risk of HIV. Despite a number of randomized controlled trials demonstrating its efficacy, and several ongoing implementation projects, PrEP is currently only available in a few countries. Modelling studies can provide useful insights into the long-term impact of introducing PrEP in different subgro...