GEMS Research



Pre-exposure prophylaxis (PrEP) is a critically important method to reduce HIV-1 incidence. However, using the same ARVs for prevention and first-line treatment increases concern about the selection and spread of HIV drug resistance. Clinical trial data have shown that the greatest risk of drug resistance with the use of ARV-based PrEP occurs when HIV-positive individuals start PrEP or continue using PrEP before they know they are infected.  Identifying the optimal frequency of HIV testing, to reduce the risk of an HIV-positive individual initiating or continuing PrEP use, will help minimize the risk of resistance.


Project Goals

Laboratory studies

Comprehensively characterize resistance risk as learned from PrEP clinical trials and demonstration studies to understand the duration of time an infected person can be on product before resistance is selected as well the impact of resistance on response to future ART regimens.

Mathematical Modeling

Use mathematical modeling to identify the most effective and efficient HIV testing and resistance monitoring strategies during PrEP roll-out.

Policy Development

Generate policy recommendations for HIV diagnostic testing frequency and ARV resistance monitoring based on laboratory and modeling data.

Resistance Monitoring During Roll-Out

Monitor seroconverters from PrEP roll-out programs for ARV resistance in selected clinics in countries in sub-Saharan Africa.


Click here for a GEMS card summarizing the above information.