The CDC's surprise guidance last week freeing the fully vaccinated to go maskless sowed plenty of concerns across the country— even earning the Saturday Night Live treatment for all the questions it spurred.

Why it matters: With plenty of Americans still unvaccinated — and without any good way to confirm who has been vaccinated — some experts worry this could put many at increased risk.

Driving the news: CDC Director Rochelle Walensky made the rounds on the Sunday news shows defending the guidance.

• Walensky said the CDC is following the science, pointing specifically to new evidence that those who are vaccinated rarely transmit the virus.
• "This is not permission for widespread removal of masks. For those who are vaccinated, it may take some time for them to feel comfortable removing their masks," Walensky told ABC News' Martha Raddatz. "But also, these decisions have to be made at the jurisdictional level, at the community level."

Among those joining the chorus of criticism were public health experts like Leana Wen, visiting professor at the George Washington University Milken Institute School of Public Health.

• The course reversal "could end up increasing confusion, removing incentives for those yet to be inoculated and delaying the eventual goal of herd immunity that would get society truly back to normal," Wen wrote in the Washington Post over the weekend.
• The largest nurses union in the U.S. called on the CDC to reverse the guidance, saying it "threatens the lives of patients, nurses, and other frontline workers across the country."

Among key concerns: Plenty of Americans have only recently qualified to begin getting their shots or can't get shots, including children younger than 12.

• "My blood is boiling that @CDCgov acted so irresponsibly to adopt an “honor code” for public mask-wearing," tweeted Ann O'Leary, former senior policy advisor to Hillary Clinton's 2016 presidential campaign. "It’s not good public health advice to say to parents whose kids can’t get vaccinated, just trust the public to do the right thing."
• The CDC clarified Saturday that schools should continue to follow guidance recommending masks indoors for the rest of this school year.

Several major companies including Walmart, Costco, Trader Joe's and Publix announced they would no longer require masks for vaccinated customers. Home Depot and Target are among those who've told customers to keep masks on for now.

Some organizations fear it will lead to an uptick in confrontations.

• "Essential workers are still forced to play mask police for shoppers who are unvaccinated and refuse to follow local COVID safety measures. Are they now supposed to become the vaccination police?" said Marc Perrone, president of The United Food and Commercial Workers International in a statement.

State of play: Some Republicans questioned the timing of the announcement, saying it was aimed at serving as a distraction from an otherwise challenging week for Biden Administration.

• Turns out, the White House may have been caught off guard by last week's announcement, the Washington Post reported. But that, in itself, has raised the question about the bungling of the message. “It’s the right decision wrongly handled," a source told the Post.
• Walensky told Fox News Sunday that political pressure had nothing to do with the agency's sudden announcement, Axios' Orion Rummler writes.