Dr. Rochelle Walensky likens the call she got from the Biden team, asking her to lead the CDC amid a pandemic, to a hospital alarm that goes off when a patient’s heart has stopped. “I got called during a code,” she says. “And when you get called during a code, your job is to be there to help.”

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)