The senior U.S. health official who first warned the coronavirus pandemic would cause “a significant disruption” on American lives is reportedly resigning.

Dr. Nancy Messonnier, according to The Washington Post, is resigning her position as director of the National Center for Immunization and Respiratory Diseases (NCIRD). Messonnier has held the position since 2016.

During the first part of 2020, Messonnier led most of the CDC’s media briefings on the coronavirus and, in February of last year, first sounded the alarm on the approaching global health crisis.

“The coronavirus outbreak is rapidly evolving and spreading,” said Messonnier during a Feb. 25, 2020, media briefing. “Cases are appearing worldwide without a known source of exposure, and successful containment at U.S. borders is becoming problematic.

“There is no vaccine or drug available to treat it,” she said, recounting a conversation with her children that morning, in which she said the family should prepare for a possibly significant disruption to their lives as a result of the outbreak.

Messonnier began her public health career in 1995 as an epidemic intelligence service officer. She served as acting director for the Center for Preparedness and Response for four months in 2019; deputy director of NCIRD from October 2014 to March 2016, and led the meningitis and vaccine preventable diseases branch in the NCIRD from 2007 to 2012.

Messonnier, according to her CDC biography, has experience in prevention and control of bacterial meningitis and played a pivotal role in a public-private partnership to develop and implement a low-cost vaccine to prevent epidemic meningococcal meningitis in Africa. More than 150 million people in the African meningitis belt have been vaccinated with MenAfriVac since 2010.

Messonnier has also participated in CDC’s preparedness and response to anthrax, including during a 2001 intentional anthrax release.

She received her bachelor of arts degree from the University of Pennsylvania and doctorate from the University of Chicago School of Medicine and completed internal medicine residency training at the University of Pennsylvania.