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Getting to Know PEP and PreP

By Sean R. Hosein

March 2012

In Canada and other high-income countries, the widespread availability of potent combination therapy for HIV, commonly called ART or HAART, has made deaths due to AIDS-related infections uncommon compared to the time before such therapies were available. Moreover, the benefit of ART is so profound that researchers expect that someone who is infected and diagnosed today and does not have other serious health conditions will likely live a near-normal life span.

ART, combined with a range of other measures, can significantly reduce the risk of HIV transmission from an HIV-positive mother to her baby. Anti-HIV drugs are taken by the mother-to-be during pregnancy and birth and then given to the baby for several weeks after birth.

In a clinical trial called iPrEX, a combination of anti-HIV drugs -- tenofovir and FTC -- sold in a fixed-dose pill called Truvada was found to reduce the risk of becoming HIV positive by 44% among gay and bisexual men and transgender women, compared to placebo. Some other clinical trials have found PrEP to reduce the risk of HIV infection for heterosexual men and women.

These examples show that anti-HIV drugs can help reduce the risk of infection. Taking anti-HIV drugs before being exposed to the virus is called pre-exposure prophylaxis (PrEP). Taking anti-HIV drugs after possible exposure to HIV to prevent infection (as is the case with babies born to HIV-positive mothers or in people who may have been exposed to HIV through needle-stick injuries or sexual exposure) is called post-exposure prophylaxis (PEP).

This article was provided by Canadian AIDS Treatment Information Exchange. It is a part of the publication TreatmentUpdate. You can find this article online by typing this address into your Web browser:

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