For C.D.C.’s Walensky, a Steep Learning Curve on Messaging

Two days before Christmas, with the Omicron variant driving a near-vertical rise in new coronavirus cases, the director of the Centers for Disease Control and Prevention alerted the White House that she planned to recommend that people infected with the virus isolate for five days instead of 10.

The director, Dr. Rochelle P. Walensky, had faced previous criticism for issuing recommendations that confused the public and in some cases caught the White House off guard. Determined to avoid that this time, she briefed other top Biden health officials on her...