Leah C. Katzelnick, Ph.D., M.P.H.

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.

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.

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.