What are biomedical interventions for HIV Prevention?

This study is exploring the acceptabiltiy of two biomedical interventions for HIV prevention:

  • Pre-exposure prophylaxis (PrEP)
  • Treatment as Prevention (TasP)

Pre-Exposure Prophylaxis (PrEP)

PrEP is the use of ARVs by HIV-negative individuals before exposure to HIV

The iPrEX study demonstrated that a daily dose of oral PrEP could reduce the risk of HIV transmission by up to 73% if adherence was high (90%) in HIV negative sexual partners in sero-discordant relationships.  In the United States, findings from iPrEX and other PrEP trials resulted in the US Food and Drug Administration (FDA) approval of Truvada (emtricitabine/tenofovir disoproxil fumarate) for use as PrEP in July 2012.  However, PrEP is not currently available available in the UK.

For more information and news on PrEP, see aidsmap.

Treatment as Prevention (TasP)

TasP is when people living with HIV start taking ARVs at the point of diagnosis, or shortly thereafter,to reduce risk of HIV transmission.

TasP already used effectively to prevent mother to child transmission, is also being advocated as a means to manage and reduce sexual transmission of HIV.  The HPTN 052 trial found that starting HIV-positive sexual partners on ARVs early (i.e. before their CD4 count dropped below the levels of 200-350 cells/μL currently advised in international guidelines for treatment initiation)  resulted in a 96% reduction in HIV transmission amongst serodiscordant couples. Recent BHIVA treatment guidelines recommend individual discussions with HIV positive patients if a patient with a CD4 cell count >350cells/μL wants to start treatment to reduce the risk of HIV transmission.

For more information and news on TasP, see aidsmap.