Kathryn E. Stephenson, M.D., M.P.H.

Kathryn E. Stephenson, M.D., M.P.H.

Principal Investigator and CTU Principal Investigator
Stephenson Laboratory

Associate Professor of Medicine- Harvard Medical School; Ragon Institute of MGH, MIT, and Harvard

Director, Clinical Trials Unit, Center for Virology and Vaccine Research- Beth Israel Deaconess Medical Center

T: 617-735-4556
F: 617-735-4566

Dr. Stephenson is a physician-scientist in the Center for Virology and Vaccine Research (CVVR) and the Division of Infectious Diseases at Beth Israel Deaconess Medical Center (BIDMC) in Boston, Massachusetts. She is also an Associate Professor of Medicine at Harvard Medical School. She has expertise in conducting phase 1 clinical trials testing novel immunologic interventions for HIV and emerging infectious diseases like SARS-CoV-2 and Zika virus. During the COVID-19 pandemic, she was the site Principal Investigator for the first-in-human trial of the Johnson & Johnson/Janssen Ad26.COV2.S COVID-19 vaccine, as well as for the Phase 3 efficacy trials of remdesivir, Novavax vaccine, and casirivimab and imdevimab monoclonal antibodies. She is currently the protocol co-chair of CoVPN 3006, the largest federally-funded study to test whether the Moderna COVID-19 vaccine can block SARS-CoV-2 transmission. This COVID-19 work complements her previous contributions in testing a mosaic Ad26-based HIV vaccine and broadly neutralizing antibodies for HIV prevention, treatment and remission. In addition, Dr. Stephenson is an outspoken advocate for increasing research equity for Black and Latinx populations in clinical trials, and is committed to ensuring access to promising medicines and vaccines for our most vulnerable communities.

Dr. Stephenson received her medical degree from New York University, and completed her internal medicine training at Columbia NY Presbyterian Hospital, followed by infectious diseases training at Mass General Brigham. She also obtained a Masters in Public Health from Columbia University where she focused on the ethics of clinical trials, isolation and quarantine.


  • Williams College, Williamstown, MA, B.A., 1996 (Anthropology)
  • Joseph L. Mailman School of Public Health, Columbia University, New York, NY, M.P.H., 2001
  • New York University School of Medicine, New York, NY, M.D., 2005


  • Residency, Columbia University Medical Center, 2005-2008 (Internal Medicine)
  • Clinical Fellowship, Massachusetts General Hospital, Brigham and Women’s Hospital, 2008-2009 (Infectious Diseases)
  • Postdoctoral Fellowship, Center for Virology and Vaccine Research, Beth Israel Deaconess Medial Center, 2009-2011 (Immunology)


  • 1997-1999, Research Assistant/Associate, HIV/AIDS Division, San Francisco General Hospital, University of California, San Francisco, San Francisco, CA
  • 2000, Intern, Joint United Nations Programme on HIV/AIDS (UNAIDS), Geneva, Switzerland
  • 2007, Jay I. Meltzer Fellow in Medical Ethics, Columbia University, New York
  • 2011-2016, Associate Physician, Division of Infectious Diseases, Brigham and Women’s Hospital, Boston, MA
  • 2011-2015, Instructor in Medicine, Harvard Medical School, Boston, MA
  • 2011-2016, Consulting Staff, Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA
  • 2014-present, Staff Physician, Division of Infectious Diseases, BIDMC, Boston, MA
  • 2015- 2023, Assistant Professor of Medicine, Harvard Medical School
  • 2017-present, Associate Member, Ragon Institute of MGH, MIT and Harvard
  • 2023 – present, Associate Professor of Medicine, Harvard Medical School


  • 1994 Gargoyle Society Alumni Scholarship, Williams College
  • 1995 Ruchman Fellow, Oakley Center for Humanities and Social Sciences, Williams College
  • 1996 Benjamin B. Wainwright 1920 Prize in English, Williams College
  • 2005 Jack and Diana Nelson Award for Scholarship and Professionalism, NYU School of Medicine
  • 2008 13th Annual Joseph N. Muschel Award, Columbia University, New York-Presbyterian Hospital
  • 2011 AIDS Vaccine 2011 Conference Scholarship, Global HIV Vaccine Enterprise
  • 2012 AIDS Vaccine 2012 Conference Scholarship, Global HIV Vaccine Enterprise
  • 2013 Maxwell Finland Award for Research Excellence, Massachusetts Infectious Diseases Society
  • 2014 Center for AIDS Research Scholar Award, Harvard University
  • 2016 103.3 AMP Radio Badass Chick of the Week
  • 2016 The Omololu Falobi Award for Excellence in HIV Prevention Research Community Advocacy, Global HIV Vaccine Enterprise


  • Cassidy T, Stephenson KE, Barouch DH, Perelson AS (2024) Modeling resistance to the broadly neutralizing antibody PGT121 in people living with HIV-1. PLOS Computational Biology 20(3): e1011518. https://doi.org/10.1371/journal.pcbi.1011518

  • Stephenson KE, Marcelin JR, Pettifor AE, Janes H, Brown E, Neradilek M, Yen C, Andriesen J, Grunenberg N, Espy N, Trahey M, Fischer RSB, DeSouza CA, Shisler JL, Connick E, Houpt ER, Chu HY, McCulloh RJ, Becker-Dreps S, Vielot NA, Kalbaugh CA, Cherabuddi K, Krueger KM, Rosenberg M, Greenberg RN, Joaquin A, Immergluck LC, Corey L, Kublin JG. Efficacy of Messenger RNA-1273 Against Severe Acute Respiratory Syndrome Coronavirus 2 Acquisition in Young Adults From March to December 2021. Open Forum Infect Dis. 2023 Nov 2;10(11):ofad511. doi: 10.1093/ofid/ofad511. PMID: 38023544; PMCID: PMC10655942. [Article]

  • Aid M, Stephenson KE, Collier AY, Nkolola JP, Michael JV, McKenzie SE, Barouch DH. Activation of coagulation and proinflammatory pathways in thrombosis with thrombocytopenia syndrome and following COVID-19 vaccination. Nat Commun. 2023 Oct 23;14(1):6703. doi: 10.1038/s41467-023-42559-x. PMID: 37872311; PMCID: PMC10593859. [Article]

  • Sobieszczyk ME, Mannheimer S, Paez CA, Yu C, Gamble T, Theodore DA, Chege W, Yacovone M, Hanscom B, Heptinstall J, Seaton KE, Zhang L, Miner MD, Eaton A, Weiner JA, Mayer K, Kalams S, Stephenson K, Julg B, Caskey M, Nussenzweig M, Gama L, Barouch DH, Ackerman ME, Tomaras GD, Huang Y, Montefiori D; HVTN 130/HPTN 089 Study Team. Safety, tolerability, pharmacokinetics, and immunological activity of dual-combinations and triple-combinations of anti-HIV monoclonal antibodies PGT121, PGDM1400, 10-1074, and VRC07-523LS administered intravenously to HIV-uninfected adults: a phase 1 randomised trial. Lancet HIV. 2023 Oct;10(10):e653-e662. doi: 10.1016/S2352-3018(23)00140-6. PMID: 37802566; PMCID: PMC10629933.https://www.sciencedirect.com/science/article/abs/pii/S2352301823001406?via%3Dihub [Article]

  • Daniel J Stieh, Dan H Barouch, Christy Comeaux, Michal Sarnecki, Kathryn E Stephenson, Stephen R Walsh, Sheetal Sawant, Jack Heptinstall, Georgia D Tomaras, James G Kublin, M Juliana McElrath, Kristen W Cohen, Stephen C De Rosa, Galit Alter, Guido Ferrari, David Montefiori, Philipp Mann, Steven Nijs, Katleen Callewaert, Paul A Goepfert, Srilatha Edupuganti, Etienne Karita, Michael S Seaman, Lawrence Corey, Lindsey R Baden, Maria G Pau, Hanneke Schuitemaker, Frank Tomaka, the ASCENT/HVTN118/HPX2003 Study Team , Safety and Immunogenicity of Ad26-Vectored HIV Vaccine With Mosaic Immunogens and a Novel Mosaic Envelope Protein in HIV-Uninfected Adults: A Phase 1/2a Study, The Journal of Infectious Diseases, Volume 227, Issue 8, 15 April 2023, Pages 939–950, https://doi.org/10.1093/infdis/jiac445 [Article]

  • Barouch DH, Stephenson KE, Sadoff J, Yu J, Chang A, Gebre M, McMahan K, Liu J, Chandrashekar A, Patel S, Le Gars M, de Groot AM, Heerwegh D, Struyf F, Douoguih M, van Hoof J, Schuitemaker H. Durable Humoral and Cellular Immune Responses 8 Months after Ad26.COV2.S Vaccination. N Engl J Med. 2021 Jul 14:NEJMc2108829. doi: 10.1056/NEJMc2108829. Epub ahead of print. PMID: 34260834; PMCID: PMC8314733. [Article]

  • Stephenson KE, Le Gars M, Sadoff J, de Groot AM, Heerwegh D, Truyers C, Atyeo C, Loos C, Chandrashekar A, McMahan K, Tostanoski LH, Yu J, Gebre MS, Jacob-Dolan C, Li Z, Patel S, Peter L, Liu J, Borducchi EN, Nkolola JP, Souza M, Tan CS, Zash R, Julg B, Nathavitharana RR, Shapiro RL, Azim AA, Alonso CD, Jaegle K, Ansel JL, Kanjilal DG, Guiney CJ, Bradshaw C, Tyler A, Makoni T, Yanosick KE, Seaman MS, Lauffenburger DA, Alter G, Struyf F, Douoguih M, Van Hoof J, Schuitemaker H, Barouch DH. Immunogenicity of the Ad26.COV2.S Vaccine for COVID-19. JAMA. 2021 Mar 11:e213645. doi: 10.1001/jama.2021.3645. Epub ahead of print. PMID: 33704352; PMCID: PMC7953339. [Article]

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  • Sadoff, Jerald, Georgi Shukarev, Dirk Heerwegh, Carla Truyers, Anne M. De Groot, Jeroen Stoop, Sarah Tete, Wim VanDamme, Isabel Leroux-Roels, Pieter-Jan Berghmans, Murray Kimmel, Pierre Van Damme, Jan De Hoon, William Smith, Kathryn Stephenson, Stephen De Rosa, Kristen Cohen, Juliana McElrath, Emmanuel Cormier, Gert Scheper, Dan Barouch, Jenny Hendriks, Frank Struyf, Macaya Douoguih, Johan Van Hoof, and Henneke Schuitemaker. "Interim Results of a Phase 1–2a Trial of Ad26.COV2.S Covid-19 Vaccine." The New England Journal of Medicine (2021). Print. [Article]