The purposes of this study are to determine whether Carraguard® Gel can prevent the transmission of HIV when used during vaginal intercourse, and to confirm that the gel is safe for vaginal use.

This study is designed to show if Carraguard® can protect women against HIV if it is used before sex, and is safe for long-term use.

Inclusion Criteria:

• HIV negative and agree to be tested for HIV and told their results at all visits during the study
• Aged 16 - 40 years of age
• Have had at least one vaginal intercourse within the last three months
• Willing and able to give written informed consent (or if desired, consent provided by parent or guardian with written assent from the minor participant)
• Provide locator information to study staff throughout the trial
• Comply with all aspects of the study protocol, including random assignment to the Carraguard® plus condom or placebo plus condom arm, clinical valuations, specimen collection and testing, visit schedule and study drug regimen
• Citizen or permanent resident of South Africa
• Resident for the past year and intends to reside in the catchment area of the site for the next two years
• During the study, will not use any vaginal products except tampons or those prescribed or approved by the study clinician.

Exclusion Criteria:

• Currently pregnant, or indicate a desire to become pregnant in the next two years at the time of screening
• Within four weeks of last pregnancy outcome at the time of enrolment
• Pap smear at screening is graded as carcinoma.
• Injected illicit drugs in the 12 months prior to screening
• Participating in any other clinical trial/HIV prevention study