Dr. Rochelle Walensky took over as director of the CDC on Jan. 20, 2021.

FILE – In this Tuesday, Dec. 8, 2020 file photo, Dr. Rochelle Walensky, speaks during an event in Wilmington, Del., to announce President-elect Joe Biden’s health care team. Walensky, 51, an infectious-diseases specialist formerly at Harvard Medical School and Massachusetts General Hospital, became CDC director on Wednesday, Jan. 20, 2021. (AP Photo/Susan Walsh)