CDC director: Difficult to issue guidances with an "ever-evolving" virus

What they're saying: "This is hard," Walensky told host Bret Baier. "We have ever-evolving science with an ever-evolving variant and my job is to provide updated guidance in the context of rapidly rising cases."

• That "is what we've done and I'm here to explain it to the American people and I'm committed to continuing to do so and to continuing to improve," she added.
• "I will say is the most important thing we can do is get our children vaccinated, get our teachers vaccinated, get our teenagers vaccinated and then to practice all of those layers of mitigation strategies that have been proved to work."

The big picture: Last week, the CDC clarified that people who have "access to a test" and want "to test" can do so but ultimately did not make a negative test a requirement to leave isolation, Axios' Tina Reed writes.

• The agency also said it did not require tests because "a negative antigen test does not necessarily indicate the absence of transmissible virus."