Treatment-as-prevention (TasP) refers to the use of antiretroviral (ARV) medication to decrease the risk of HIV transmission.

TasP frequently refers to the prevention method that involves prescribing antiretrovirals (ARVs) to those who are infected with HIV in order to reduce the amount of virus in their blood (and genital fluids) so that they are less likely to infect others.

In 2011, the HIV Prevention Trials Network (HPTN 052) study demonstrated that the use of ARVs by HIV-positive heterosexual men and women cut the chance that their HIV negative partner would become infected by roughly 96 percent. The final study results (announced in 2015) found that no participant with a fully suppressed viral load infected his or her long-term HIV-negative partner.

In 2014, interim analysis of the ongoing PARTNER trial—which focuses on heterosexual and gay mixed-HIV status couples in which the HIV-positive partner is taking ARVs—found that there were no transmissions of the virus within the couples. The trial is set to complete in 2017.

The U.S. Department of Health and Human Services now recommends ARV treatment for all people living with HIV, regardless of their CD4 cell count, based in part on the findings of HPTN 052 and other studies.

The success of TaSP is dependent on people adhering to their HIV treatment.

While it is acknowledged that TaSP alone will not end the global HIV epidemic, it is an essential part of the HIV prevention toolbox.

Other examples of treatment as prevention include:

Last Revised: February 14, 2016