Since the early days of her time as Director for the Centers for Disease Control and Prevention, Dr. Rochelle Walensky has made comments and claims over Covid-19 guidance that her own agency, and sometimes the White House, have walked back or toned down.

While some of Walensky's comments might be explained by the gap between more conversational language and official written recommendations, the CDC under President Joe Biden has been criticized for its guidance in the past -- for either being too conservative or too lenient. Thus, the whiplash from Walensky's comments and the subsequent clarifications and revisions might help explain a lack of public confidence that exists among Americans toward the agency.

Most recently, Walensky told a Senate committee Wednesday that data now shows fully vaccinated individuals can't pass Covid-19 to other people.

"Data have emerged again that [demonstrate] that even if you were to get infected during post vaccination that you can't give it to anyone else," Walensky said in response to a question about the new CDC guidance for vaccinated people and masks.

The CDC's website, however, continues to say that vaccines only "reduce the risk of people spreading COVID-19" not that people "can't" spread it post-vaccination. The CDC did not respond to CNN's request for clarification.