The new CDC mask guidelines are confusing and could actually make the spread of COVID-19 worse, a group of leading physicians said

• The CDC's new mask guidance could lead more people to catch COVID-19 indoors, experts said.
• They said the CDC got the science right for fully vaccinated people but needed to give more context.
• The guidelines could give the "misimpression" mask mandates are over, they said.

New federal mask guidance that says fully vaccinated Americans can go maskless in most settings risks more people catching the coronavirus at work or in public, a leading expert has warned.

Dr. Jeffrey Duchin, a physician at the Infectious Diseases Society of America, said that the Centers for Disease Control and Prevention's latest guidance was scientifically sound but that the public-health agency had not given enough detail in its guidance, allowing for the "misimpression" that mask mandates had been lifted.

Therefore, the guidelines "could lead to increased risk in public spaces and workplaces with preventable COVID-19 spread primarily among the unvaccinated," he said at a press briefing Thursday hosted by the IDSA.

The CDC guidance recommended that unvaccinated people still wear masks. Regardless, the recommendations are not legally binding, and businesses and states are allowed to make their own rules.

Duchin said the information from the CDC was "suboptimal."

"The return to normal activities is safe for vaccinated people, there is no debate about this fact; however, the announcement led to widespread confusion and frustration because it was unexpected and needed context," Duchin, the society's liaison to the CDC immunization committee, said.

"There was no information on how to apply the guidance in practice, particularly related to the inability to verify vaccination status," he said.

Duchin suggested that the CDC shouldn't have issued a blanket statement but instead made recommendations according to the number of coronavirus cases or the proportion of vaccinated people in an area.

So far, less than 40% of Americans are fully vaccinated, according to the CDC. Less than 30% of people in Wyoming are fully immunized, the lowest of any state, according to data from Johns Hopkins University.

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Most states, however, have followed the CDC's more relaxed guidelines.

Duchin, who is also the health officer for King County in Washington, which includes Seattle, issued a directive Thursday that strongly urged all Washingtonians older than 5 years old to continue to wear face coverings in indoor public spaces. Washington's governor, Jay Inslee, said in the wake of the CDC's update on May 13 that individual businesses might require masks for vaccinated people but there was no state requirement.

Duchin told the University of Minnesota's Center for Infectious Disease Research and Policy that King County needed "more time to get disease rates down and vaccination rates up before doing anything that would weaken our indoor mask mandates."

"The CDC guidance makes absolute sense in many areas, but many places are not there yet," he said.

Duchin's comments followed a joint statement from the IDSA and the HIV Medicine Association issued Monday that acknowledged the CDC's recommendations were based on science but said the "CDC should not send a message that the pandemic is over."

Insider's Aria Bendix reported May 13 that other experts said the CDC's guidance was too broad.

Dr. Leana Wen, a former Baltimore health commissioner who is a contributing columnist at The Washington Post and a medical analyst for CNN, told CIDRAP that the CDC got "the science right, but policy and communication was really wrong."

"There are unintended consequences that can endanger people and sew distrust in the CDC," Wen said.

Dr. Anthony Fauci said Wednesday that people were misinterpreting the CDC's guidance but that it wasn't the CDC's "fault."

"People either read them quickly, or listen and hear half of it," Fauci said. "They are feeling that we're saying: 'You don't need the mask anymore.' That's not what the CDC said."