Why Do People Use PEP?
Interest in using anti-HIV therapy to decrease the risk of establishing HIV infection is based on three observations. One is the observation of fewer HIV infections among health care workers with occupational exposures to HIV when anti-HIV therapy was used within hours of the exposure. Another are results from studies which show that therapy given to HIV-positive pregnant women during pregnancy/labor and to newborn children for their first six weeks of life reduces the risk of mother-to-child HIV transmission rates from 25% to about 8%. In this study, not all children received anti-HIV therapy for 6 weeks, but HIV rates were lowest among the children who did — which is perhaps the strongest argument for using PEP. There have also been animal studies where, in some cases, using PEP prevented the establishment of infection in the sexual exposure setting. These results suggest that PEP may also lower the risk of HIV infection in possible exposures in other settings, such as human sexual
