Navigating Human Immunodeficiency Virus Screening Recommendations for People on Pre-Exposure Prophylaxis and the Need to Update Testing Algorithms

The incident HIV infections that rarely occur in individuals on pre-exposure prophylaxis (PrEP) for HIV prevention may be associated with atypical or delayed seroconversion and have highlighted key problems with the widely used fourth generation HIV screening tests that assess for HIV p24 antigen and HIV-1/-2 antibodies. Recently updated CDC guidelines for management of people on PrEP now recommend the addition of HIV-1 RNA testing to antigen/antibody screening every 3 months for individuals on oral and injectable PrEP. We believe that in the context of available evidence and limited laboratory capacity, this should be done routinely only for individuals on injectable cabotegravir, and that antigen/antibody testing (without routine RNA testing) remain the test of choice for individuals on tenofovir-based PrEP formulations. Development of alternative HIV screening strategies that combine antibody and clinic-based rapid viral load testing would make it feasible to role this out to all individuals on PrEP.