Julia Marcus, PhD, MPH

Julia Marcus is an infectious disease epidemiologist and Associate Professor in the Department of Population Medicine at Harvard Medical School and Harvard Pilgrim Health Care Institute, and Adjunct Faculty at The Fenway Institute. She received her doctoral degree in epidemiology from the University of California, Berkeley, and completed a postdoctoral fellowship at the Kaiser Permanente Division of Research.

As her primary research interest, Dr. Marcus focuses on improving the implementation of preexposure prophylaxis (PrEP) to prevent new HIV infections and promote sexual health in the United States. She has used electronic health record, survey, and qualitative data to identify people likely to benefit from PrEP, evaluate clinical outcomes among PrEP users in real-world healthcare settings, and characterize gaps and inequities in the PrEP continuum of care.

Dr. Marcus conducts research that has a direct impact on policy and clinical practice. Her studies are cited by the Centers for Disease Control and Prevention in multiple clinical guidelines and as key evidence of the effectiveness of PrEP. Research she led on life expectancy for people with HIV contributed to the Equal Insurance HIV Act, a California state law that protects people with HIV from discrimination by insurance companies. Her research on hepatitis C infection led to the elimination of national race-based treatment guidelines that had restricted the use of shorter courses of hepatitis C treatment for Black people.

Most recently, Dr. Marcus is leading multiple projects funded by the National Institutes of Health, including a randomized trial of an electronic decision support tool with an embedded HIV prediction model to improve PrEP prescribing in safety-net clinics, a study on the implementation of long-acting injectable PrEP, and formative research to evaluate the feasibility and acceptability of over-the-counter PrEP.

In addition to her research, Dr. Marcus has written essays on public health, including a series of articles in The Atlantic during the Covid-19 pandemic.