<qa>  What is the lowest risk for HIV-1?- Low risk for HIV-1 no sexually transmitted disease within 1 year of study entry, no history of injection drug use, no sex with an HIV infected individual or active injection drug user within 6 months of study entry, no unsafe sexual activity with unknown partners or mutually monogamous relationship with a known HIV seronegative partner per subject report for 6 months prior to study entry 