Mask mandates are lifting. Experts say here's when to consider keeping yours on.

It's not time to get rid of masks yet, but it could be soon, say health experts.

Their advice comes as pubic exhaustion and anger at masking mandates is growing, and 40% of adults say they wear masks only some of the time or never, according to a Yahoo/YouGov survey.

Meanwhile, multiple states are lifting mask mandates, sometimes without hard scientific backing or support.

On Wednesday Dr. Rochelle Walensky, director of the Centers for Disease Control and Prevention, said the decision to mask should be made at the local level and the agency is working on guidance.

Amid the confusion, USA TODAY asked a dozen public health and infectious disease experts whether it makes sense for people to continue to wear masks and under what conditions.

The answer, they say, depends on how much someone wants to avoid infection, the rate of COVID-19 where they live and who else is around them. 

"People are going to have to make their own decision about what risk they're personally willing to tolerate," said Dr. Susan Kline, an epidemiologist and professor of infectious diseases at the University of Minnesota medical school.

"Masks aren't perfect but they substantially lower your chance of getting COVID-19," she said.

Studies find that masks, especially N95s and KN95s, work very well at protecting people in indoor public settings – even if no one else is wearing one.

A CDC study published Wednesday found that people who always wear either an N95 or a KN95 in indoor public places lowered their odds of testing positive for COVID-19 by 83%.

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"One-way masking with a high quality mask protects the wearer, even if others around you aren't masking," said Dr. Leana Wen, an emergency physician and public health professor at George Washington University.

The protection "isn't perfect," but it's pretty good, said William Hanage, an epidemiologist at the Harvard T.H. Chan School of Public Health.

He said he personally will keep wearing a mask to places like the grocery store until COVID-19 infection rates come down to their lows of last spring. "I see little downside to mask use in many contexts,"  he said.

When to drop the mask

Infection rates are still too high nationwide to do away with masks just yet, said Dr. William Schaffner, a professor of preventive medicine and infectious disease at Vanderbilt University of Tennessee.

He wants to see cases of COVID-19 fall for eight straight weeks "to make sure this is over." Cases have dropped for four weeks in the U.S. since the omicron peak the week ending Jan. 15.

Lower levels of circulating COVID-19 are crucial, said Dr. Carlos del Rio, an infectious disease expert at Emory University School of Medicine in Atlanta. 

"If 1 in 10 individuals are infected in a community, the risk is very different than if 1 in 1,000 persons is infected," he said. 

He thinks infection levels will have fallen enough by early March to make unmasking make sense for most people, especially those who are fully vaccinated and boosted.

Much depends on what happens with the highly-transmissible omicron variant in the next two weeks, said Dr. Peter Hotez, co-director of the Texas Children’s Hospital Center for Vaccine Development.

In one scenario, omicron continues to decline and transmission is very low.

"In this case, we can feel more comfortable loosening mask restrictions, although some may choose to continue with masks for the time being," he said.

On the other hand, if the BA.2 omicron sub-variant accelerates, it could extend the current COVID-19 wave for another six weeks, he said.

It's all about being confident there is so little virus in the community that transmission in a public place is unlikely, said Dr. Eric Topol, a professor of molecular medicine at Scripps Research.

"I will only stop wearing a mask indoors when I am confident the level of circulating virus is low enough to be confident," he said.

Long-time mask proponent Dr. Monica Gandhi, an infectious disease specialist at the University of California, San Francisco, said that as COVID-19 rates fall, she'd be ready to uncover.

"I am not planning to wear a mask indoors in public spaces (except at the hospital) because I am immunocompetent, vaccinated and boosted," she said.

That advice is different for someone who's over 65, immunocompromised or has a risk factor for severe COVID-19, such as heart disease, diabetes or obesity.

"I have told my father, who is 87 and currently immunocompromised from being on chemotherapy, that he must continue to wear a well fitted and filtered mask in indoors public spaces until community transmission is very low," she said. 

There's also the question of who you spend time with. 

"In our extended family we have someone who's immunocompromised, so we're wearing our masks wherever we go for the foreseeable future," Schaffner said.

All the experts noted vaccination is the best way to end the need for masking because the great majority of people with severe disease, in the hospital and dying today are unvaccinated. 

Ultimately, when transmission rates are low, "mask optional" is the right way to think of it, said Del Rio. "You want to wear a mask? Do it!"

Contact Weise at eweise@usatoday.com and Weintraub at kweintraub@usatoday.com 

Health and patient safety coverage at USA TODAY is made possible in part by a grant from the Masimo Foundation for Ethics, Innovation and Competition in Healthcare. The Masimo Foundation does not provide editorial input.