PrEP and TasP

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PrEP and TasP

What is Pre-Exposure Prophylaxis (PrEP)?

Pre-Exposure Prophylaxis (PrEP) is an HIV prevention approach for HIV-negative individuals that uses anti-HIV drugs (antiretrovirals – ARVs) as a method to prevent acquisition of HIV.

Truvada, an FDA approved anti-HIV drug, is the only option currently available for use as PrEP.

  • To be most effective as PrEP, Truvada should be taken consistently and correctly.
  • Truvada should be prescribed by a medical provider and taken once daily by mouth.
  • Regular medical appointments should be scheduled for HIV testing and to monitor overall health.

PrEP has shown to be very effective when used as prescribed in combination with regular HIV testing and other proven prevention methods such as condoms or treatment as prevention (TasP).

PrEP is much less effective when not taken consistently.

New delivery methods for PrEP are being studied. These options could release anti-HIV drugs into the body over a period of several months and prevent the acquisition of HIV. These include:

  • Implantables: tiny rods placed just beneath the surface of the skin by a medical provider.
  • Injectables: shots given by a medical provider.

Illustration by Kimberly Carney / Fred Hutch News Service

Is PrEP a cure for HIV?

PrEP is part of a comprehensive HIV prevention approach, not a cure for HIV. HIV-negative individuals who have sex with people living with HIV or people of unknown HIV status may use PrEP to lower their chances of acquiring HIV if they are exposed to it.

Doctors may prescribe the same drugs contained in Truvada to patients living with HIV as part of a broader treatment regimen, but “PrEP” refers to an HIV prevention strategy for HIV-negative individuals and is not used by people living with HIV to treat HIV infection.


What is Treatment as Prevention (TasP)?

Treatment-as-prevention (TasP) refers to the use of anti-HIV drugs by someone who has acquired HIV to stay healthy and decrease the risk of HIV transmission to others through sex, needle sharing, or during pregnancy and birth.  

TasP works by reducing the amount of HIV in the body of someone living with HIV to very low levels (referred to as undetectable), thus making their blood, vaginal fluid, breast milk, and semen less likely to transmit HIV to others. 

TasP usually consists of at least three anti-HIV drugs taken daily.

The consistent and correct use of anti-HIV drugs to maintain decreased HIV in the body includes:

  • Taking anti-HIV drugs as prescribed by a medical provider
  • Regular medical appointments to monitor the amount of HIV in the body

People who start treatment soon after becoming HIV positive will have improved health outcomes and live longer than those who start treatment later.

For more information on TasP watch:


What is the HIV Prevention Trials Network (HPTN)?

The HIV Prevention Trials Network (HPTN) is a worldwide collaborative clinical trials network that brings together investigators, ethicists, community, and other partners to develop and test the safety and efficacy of interventions designed to prevent the acquisition and transmission of HIV. HPTN studies evaluate new HIV prevention interventions and strategies in populations and geographical regions that bear a disproportionate burden of HIV infection.

The HPTN research agenda is focused primarily on the use of integrated strategies: use of antiretroviral drugs (antiretroviral therapy and pre-exposure prophylaxis); interventions for substance abuse, particularly injection drug use; behavioral risk reduction interventions, and structural interventions. The HPTN is committed to the highest ethical standards for its clinical trials and recognizes the importance of community engagement in all phases of the research process.

The HPTN was established in 2000, building on the work of the HIV Network for Prevention Trials (HIVNET). HPTN’s Leadership and Operations Center is based at FHI 360 in Durham, NC. Its Laboratory Center is at Johns Hopkins University in Baltimore, MD. Its Statistical and Data Management Center is housed within the Statistical Center for HIV/AIDS Research and Prevention (SCHARP) at the Fred Hutchinson Cancer Research Center in Seattle, WA.

HPTN receives its funding from three NIH institutes: the National Institute of Allergy and Infectious Diseases, the National Institute of Mental Health, and the National Institute on Drug Abuse.