Nancy Messonnier (néeRosenstein; born November 1965) is an American physician who served as the director of the National Center for Immunization and Respiratory Diseases at the Centers for Disease Control and Prevention from 2016 to 2021. She worked on the CDC’s response to the COVID-19 pandemic in the United States.
Messonnier was born in Philadelphia, Pennsylvania, to Robert Rosenstein, who ran a small business, and Gerri Rosenstein, a bookkeeper and local school board president. She grew up in Lower Moreland Township, Pennsylvania, with her brother Rod Rosenstein.
Messonnier graduated from Lower Moreland High School in Lower Moreland Township. She received her Bachelor of Arts degree from the University of Pennsylvania in 1987. She then attended the University of Chicago School of Medicine, where she received her Doctor of Medicine in 1992. She then returned to the University of Pennsylvania for her residency training in internal medicine between 1992 and 1995.
Messonnier began her career in public health in 1995 as an epidemic intelligence service officer in the National Center for Infectious Diseases, a program of the Centers for Disease Control and Prevention (CDC). During her tenure at the CDC, she led the Meningitis and Vaccine Preventable Diseases Branch in NCIRD’s Division of Bacterial Diseases from 2007 to 2012. She also served as the deputy director of NCIRD from 2014 to 2016 before becoming director of the center on April 4, 2016.
During the course of her career, Messonnier notably worked on the 2001 anthrax attacks response, serving as co-leader of the anthrax management team and vaccine working group. She also played a leading role developing a low-cost meningococcal meningitis vaccine to prevent an emerging epidemic in Africa, known as MenAfriVac, in 2010. She has also worked on communications strategies to promote the use of vaccines to prevent the emergence of disease outbreaks.