Leah C. Katzelnick, Ph.D., MPH

Viral Epidemiology and Immunity Unit

Established in 2020

NIH Main Campus, Bethesda, MD

Leah C. Katzelnick, Ph.D., MPH (She/Her/Hers)

Chief, Viral Epidemiology and Immunity Unit

Contact: For contact information, search the NIH Enterprise Directory.

Photo of Leah C. Katzelnick, Ph.D., MPH

Major Areas of Research

  • Immunologically complex emerging and reemerging viral diseases, including dengue and Zika
  • Host immunologic correlates of enduring protection and disease
  • Antigenic and genetic viral evolution
  • Virus transmission dynamics

Program Description

Mosquito-borne flaviviruses infect hundreds of millions of people globally each year and cause a spectrum of life-threatening diseases, including hemorrhagic fevers, encephalitis, and severe congenital abnormalities. There are still no licensed, broadly protective vaccines against two of the most important flaviviruses: dengue virus and Zika virus. Dengue viruses 1-4 are challenging vaccine targets because sub-protective vaccines can increase risk of Dengue Hemorrhagic Fever/Dengue Shock Syndrome, the disease dengue vaccines are designed to prevent. The only licensed dengue vaccine to date significantly increases risk of severe dengue disease in those without a prior dengue virus exposure. Zika viruses emerged across the Americas in 2014-2017, causing major pandemics and congenital Zika syndrome, making development of a Zika vaccine a high priority.

Zika DENV Image

Prior Zika virus infection increases the probability of future symptomatic dengue virus infection (Katzelnick et al. Science 2020).

Credit: NIAID
 Dengue Hemorrhagic Fever

Intermediate levels of preexisting anti-dengue virus antibodies increase risk of Dengue Hemorrhagic Fever/Dengue Shock Syndrome (Katzelnick et al. Science 2017).

Credit: NIAID

The Viral Epidemiology and Immunity Unit (VEIU) uses a multidisciplinary approach to investigate immunological protection against and susceptibility to emerging and re-emerging viral diseases with the goal of informing how vaccines can be effectively and safely licensed and introduced through vaccination programs. Our work focuses on immunologically complex diseases caused by flaviviruses, including dengue and Zika viruses, as well as coronaviruses. We collaborate with research teams to study determinants of disease in longitudinal cohort and vaccine studies in Nicaragua, Thailand, Ecuador, the Philippines, and other sites. To address questions about virus antigenicity, host protective immunity, and population-level viral transmission dynamics, we use biologically relevant immunological assays and diverse computational and epidemiological methods to measure and evaluate the role of immunity in protection against disease in human cohort studies.

DENV Antigenic Map

A subset of dengue viruses of each serotype are as close to viruses of another type as to some viruses of their own type (Katzelnick et al. Science 2015).

Credit: NIAID



Ph.D., 2016, University of Cambridge

Dr. Leah Katzelnick pursued a Ph.D. studying antigenic variation among dengue viruses at the University of Cambridge and the National Institutes of Health as an NIH OxCam Scholar and Gates Cambridge Scholar. After receiving her Ph.D. in 2016, she conducted her postdoctoral work at the University of California, Berkeley and University of Florida on determinants of dengue and Zika disease, spending a year in Ecuador and Nicaragua to work closely with research teams conducting longitudinal cohort studies. In September of 2020, Leah became an Earl Stadtman tenure-track investigator and NIH Distinguished Scholar in the Laboratory of Infectious Diseases in NIAID. She is Chief of the Viral Epidemiology and Immunity Unit.

Selected Publications

Katzelnick LC, Coello Escoto A, Huang AT, Garcia-Carreras B, Chowdhury N, Maljkovic Berry I, Chavez C, Buchy P, Duong V, Dussart P, Gromowski G, Macareo L, Thaisomboonsuk B, Fernandez S, Smith DJ, Jarman R, Whitehead SS, Salje H, Cummings DAT. Antigenic evolution of dengue viruses over 20 years. Science. 2021 Nov 19;374(6570):999-1004.

Katzelnick LC, Zambrana JV, Elizondo D, Collado D, Garcia N, Arguello S, Mercado JC, Miranda T, Ampie O, Mercado BL, Narvaez C, Gresh L, Binder RA, Ojeda S, Sanchez N, Plazaola M, Latta K, Schiller A, Coloma J, Carrillo FB, Narvaez F, Halloran ME, Gordon A, Kuan G, Balmaseda A, Harris E. Dengue and Zika virus infections in children elicit cross-reactive protective and enhancing antibodies that persist long term. Sci Transl Med. 2021 Oct 6;13(614):eabg9478.

Katzelnick LC, Narvaez C, Arguello S, Lopez Mercado B, Collado D, Ampie O, Elizondo D, Miranda T, Bustos Carillo F, Mercado JC, Latta K, Schiller A, Segovia-Chumbez B, Ojeda S, Sanchez N, Plazaola M, Coloma J, Halloran ME, Premkumar L, Gordon A, Narvaez F, de Silva AM, Kuan G, Balmaseda A, Harris E. Zika virus infection enhances future risk of severe dengue disease. Science. 2020 Aug 28;369(6507):1123-1128.

Katzelnick LC, Ben-Shachar R, Mercado JC, Rodriguez-Barraquer I, Elizondo D, Arguello S, Nuñez A, Ojeda S, Sanchez N, Lopez Mercado B, Gresh L, Burger-Calderon R, Kuan G, Gordon A, Balmaseda A, Harris E. Dynamics and determinants of the force of infection of dengue virus from 1994 to 2015 in Managua, Nicaragua. Proc Natl Acad Sci U S A. 2018 Oct 16;115(42):10762-10767.

Katzelnick LC, Gresh L, Halloran ME, Mercado JC, Kuan G, Gordon A, Balmaseda A, Harris E. Antibody-dependent enhancement of severe dengue disease in humans. Science. 2017 Nov 17;358(6365):929-932.

Katzelnick LC, Fonville JM, Gromowski GD, Bustos Arriaga J, Green A, James SL, Lau L, Montoya M, Wang C, VanBlargan LA, Russell CA, Thu HM, Pierson TC, Buchy P, Aaskov JG, Muñoz-Jordán JL, Vasilakis N, Gibbons RV, Tesh RB, Osterhaus AD, Fouchier RA, Durbin A, Simmons CP, Holmes EC, Harris E, Whitehead SS, Smith DJ. Dengue viruses cluster antigenically but not as discrete serotypes. Science. 2015 Sep 18;349(6254):1338-43.

Visit PubMed for a complete publication listing.

Research Group

We use a multidisciplinary approach encompassing virology, immunology, and epidemiology to investigate protection against and susceptibility to emerging viruses to inform safe and effective deployments of vaccines. Our primary expertise is in seroepidemiology, and our research focuses dengue, which we believe serves as a model pathogen for other complex, immune-evasive viruses.

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