Introduction

• 2.1 million new HIV infections occurred worldwide in 2015^{[UNAIDS 2016]}
  • ~ 50,000 in United States^{[CDC 2014]}
• Biomedical prevention/use of antiretroviral agents to prevent at-risk HIV-negative individuals from becoming newly infected important adjuvant to behavioral risk-reduction interventions
• Strategies for biomedical prevention:
  • Treatment as prevention
  • Pre-exposure prophylaxis
  • Postexposure prophylaxis

In 2015, 2.1 million new HIV infections occurred worldwide,^{[UNAIDS 2016]} and approximately 50,000 of these transmissions occur in the United States.^{[CDC 2014]} In isolation, behavioral risk-reduction interventions have had limited success in reducing HIV incidence,^[...