Acute HIV at the Time of Initiation of Pre-Exposure or Post-Exposure Prophylaxis

Impact on Drug Resistance and Clinical Outcomes

Kelly A. Johnson, MD, MPH; Miao-Jung Chen, PhD, MPH; Robert Kohn, MPH; Darpun Sachdev, MD, MPH; Oliver Bacon, MD, MPH; Sulggi Lee, MD, PhD; Stephanie E. Cohen, MD, MPH


J Acquir Immune Defic Syndr. 2021;87(2):818-825. 

In This Article


Pre-exposure prophylaxis (PrEP) with once-daily oral tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) is a highly effective HIV prevention strategy[1,2] and a key component of the Ending the HIV Epidemic initiative in the United States.[3] Despite this, PrEP uptake remains suboptimal, used by less than 20% of those who remain at risk of HIV acquisition in this country.[1]

Same-day PrEP programs, wherein PrEP is initiated on the day that patients first present to care, can reduce wait times and improve PrEP uptake. Such programs have been shown to be safe, feasible, and effective.[4–6] When implemented in a Denver sexually transmitted disease (STD) clinic, nearly 80% of same-day PrEP clients demonstrated effective linkage to care by attending 1 or more follow-up appointments and all (100%) reported liking the option of same-day PrEP.[4] Although same-day PrEP programs do not necessarily ensure long-term retention (as demonstrated by the fact that only 57% of patients attended at least 2 follow-up visits in the Denver clinic[4]), they do address a major barrier to successful PrEP engagement—that of delays between initial presentation and PrEP start, during which time patients may be lost to follow-up. Studies of STD clinics in Chicago and primary care clinics in San Francisco have shown, respectively, that only 29% of eligible individuals receive a PrEP referral and that nearly 30% wait 30 days or more to start their prophylactic antiretroviral therapy.[7,8]

Despite the potential benefits of same-day PrEP, providers may be hesitant to initiate same-day PrEP because of concerns regarding the potential emergence of antiretroviral resistance in the face of undiagnosed acute HIV (AHI). Although resistance to TDF/FTC when used for PrEP is rare overall (occurring <0.1% of the time[1]), the risk does seem to be higher when PrEP is inadvertently prescribed to individuals with AHI.[2,9–11] Meta-analyses of previous PrEP studies have highlighted this fact, with 1 review demonstrating TDF/FTC mutations in 41% of participants with undiagnosed AHI at the time of PrEP enrollment compared with just 3% of those who acquired HIV during PrEP follow-up.[12,13]

To better understand the long-term implications of starting PrEP in the setting of AHI, we identified and characterized a series of adult patients who had as-yet-undiagnosed AHI on the same day as PrEP/post-exposure prophylaxis (PEP) initiation at a San Francisco STD clinic. Our goal was to describe HIV resistance mutations as well as clinical outcomes including time to HIV care, time to initiation of antiretroviral therapy, and time to HIV viral suppression.