Since January 2020, Messonnier has been helping lead the CDC efforts to address and combat the emerging threat of COVID-19, the disease caused by the novel coronavirus (SARS-CoV-2). When 195 Americans were evacuated out of Wuhan because of the virus, the CDC moved to quarantine all of them, with Messonnier noting: “While we realize this is an unprecedented action, this is an unprecedented threat.”

She has also addressed concerns around the CDC and FDA’s failure to get working COVID-19 testing kits into the hands of public health officials to enable better containment of the disease and for mitigation of its spread. On January 21, 2020, she had announced that the CDC had finalized its own COVID-19 test. On February 5, the CDC began distributing diagnostic tests to public-health laboratories, however, several of those tests had contaminated reagents, rendering them useless, and leading to a major gap in fighting the outbreak. The situation was exacerbated by FDA-imposed regulations on testing, making it difficult for independent development of COVID-19 tests to fill the CDC’s distribution gap.

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.

For leading the U.S. Department of Health and Human Services’ response to the 2009 influenza pandemic

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.

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.

Nancy Messonnier (née Rosenstein; born November 1965) is an American physician who now serves as the director of the National Center for Immunization and Respiratory Diseases at the Centers for Disease Control and Prevention. She is working on the CDC response to the COVID-19 pandemic in the United States.