This is an open-label, randomized, three-arm, directly observed therapy study. HIV-uninfected non-pregnant cisgender women at low risk for HIV will be randomly assigned to 1 of 3 dosing frequencies of directly observed therapy (DOT) Tenofovir Disoproxil Fumarate/Emtricitabine (TDF/FTC) PrEP to help differentiate poor and modest from perfect dosing. An additional contemporaneous cohort of pregnant to receive daily dosing will also be recruited to evaluate the impact of pregnancy on blood and cellular drug levels. Drug concentrations in blood, vaginal fluid, and tissue will be measured during the study. The primary objectives of the study are:~To define the cisgender women-specific expected blood concentrations and dose-proportionality for Tenofovir-diphosphate (TFV-DP) in dried blood spots (DBS) and Peripheral Blood Mononuclear Cells(PBMCs) using directly observed TDF/FTC therapy at 2, 4, 7 doses per week.~To establish a model to predict adherence rate to TDF/FTC by level of TFV-DP in DBS for cisgender women. HIV-uninfected non-pregnant cisgender women will be randomly assigned to 1 of 3 dosing frequencies of directly observed therapy (DOT) TDF/FTC PrEP: 2, 4, or 7 doses/week to help differentiate poor and modest from perfect adherence.~The study will be the first to define TDF-PrEP adherence-blood concentration thresholds for African cisgender women, a priority population for HIV prevention. The findings will guide accurate interpretation of adherence and success of PrEP programs in cisgender women. This data will also help guide decisions on optimal PrEP dosing for HIV at-risk pregnant cisgender women in Africa.
The study seeks to define the expected blood levels of pre-exposure prophylaxis (PrEP) medications (tenofovir) for cisgender women taking directly observed oral PrEP therapy to understand the frequency of PrEP dosing associated with HIV protection in cisgender women. Cisgender women will be randomly assigned to receive varying frequency of weekly PrEP doses and followed for up to 16 weeks. The study will also investigate how pregnancy affects the expected blood levels to help define optimal dosing of PrEP for HIV prevention during pregnancy.