walensky and the cdc have been facing a fevered pitch of criticism over those isolation and quarantine guidelines. and the confusing back and forth and the messaging over those guidelines in recent weeks. there has been frustration at the white house with the cdc's messaging operation. and also i'm told frustration within the cdc at dr. walensky and the way in which those guidelines were crafted and communi communicated. she is set to hold her first solo press briefing next hour, this is the first briefing she has done since the summer. and it comes as she has been spending the last several months undergoing media training with the prominent democratic media consultant. dr. walensky has already addressed some of the criticism she faced including just this morning. listen. >> we're working 24/7, 12,000 people to keep america safe, to update our guidance in the face of fast moving science and fast moving epidemiology.