Do you still need to wear a mask? This chart by an infectious disease expert can help you decide as mask mandates tumble

• Mask mandates and coronavirus restrictions are tumbling, as the Omicron variant continues to recede.
• Infectious disease expert Katelyn Jetelina has created a framework for how to think smartly about when and where to wear a mask.

Across the US, temperatures are warming up, and masks are coming off, as the Omicron variant continues to recede.

Many Democratic governors are beginning to unravel mask mandates for businesses that had been in place for months, while others have suggested that schoolchildren and teachers may begin taking off their masks in class in the coming weeks — for the first time during the pandemic.

"Governors are reading the tea leaves," infectious disease expert Mike Osterholm, who directs the Center for Infectious Disease Research and Policy at the University of Minnesota, said on a Thursday podcast.

"I'm not saying they shouldn't, but know that it never was based on some objective criteria. It was just 'we're done, we're tired, and it's acceptable enough now.'"

Dr. Rochelle Walensky, director of the Centers for Disease Control and Prevention, acknowledged during a White House COVID-19 briefing earlier this week that "we want to give people a break from things like mask-wearing." However, she also said that, from the CDC's perspective, that should only happen when disease "metrics are better," and hospitals aren't overflowing anymore.

"Our hospitals need to be able to take care of people with heart attacks and strokes," Walensky said. "Our emergency departments can't be so overwhelmed that patients with emergent issues have to wait in line."

In order to provide an honest and independent scientific framework for this moment, public health expert Katelyn Jetelina, an assistant professor at the University of Texas, created her own chart, which she shared with Insider (adapted below). It gives people a framework for how to "ride the waves," as she puts it, of any potential coronavirus surges from here on out.

"We need a solution that addresses the ebb and flow of viral dynamics," she wrote in a recent Substack post, "leveraging the tools we have at hand."

How to use this COVID chart

The chart is meant to be read based on two key measurements: the number of COVID-19 cases in your area, and the test positivity rate where you live. Both metrics are retrievable for all US counties on the CDC's COVID-19 dashboards.

For example, in Brooklyn, New York, while the percentage of positive tests is low (2.23%), the case rate per 100,000 still puts the borough in the red zone, at 118.25.

Jetelina's chart suggests, then, that people in Brooklyn should:

• Still avoid indoor dining, for now
• And wear masks when indoors in public

Now, let's look at Washington County, Rhode Island, one of the few places in the US that is not currently experiencing red-hot coronavirus transmission.

According to the CDC's metrics, the case rate per 100,000 is essentially zero, but Washington County still has a positive test rate of roughly 7%, putting the area in the yellow zone.

This means:

• It's relatively safe to dine indoors
• It's relatively safe to close windows
• It's relatively safe to go maskless
• But vulnerable or extra cautious people may still want to wear a mask when they're in public spaces indoors

There are still some times it's a good idea to wear a mask, even when transmission is low where you live

The reason to wear a well-fitted mask with good filtration is both to protect the wearer, and those around them, from exchanging any infectious material expelled from the mouth or the nose. This will help stop the virus from spreading further than it already is, and it is especially important to help protect the people at greatest risk of developing severe, debilitating, and deadly COVID cases, including elderly folks, and immunocompromised people.

So, if you're sick, or have been exposed to someone who is, it's still a good idea to wear a good mask around others who may be vulnerable to infection for a full 10 days.

"Removing the mandates makes sense, in settings where we think that most people that are susceptible to Omicron have been infected, and the numbers are coming down because we've run out of people to infect," Christopher Murray, lead modeler at the leading Institute for Health Metrics and Evaluation, said during a recent Q&A.

Leading experts generally agree with him that we're, potentially, moving closer toward a time when the COVID-19 outbreak isn't an all-out public health crisis, at least for as long as the Omicron variant continues to control all infections.

Top US disease modelers working with Murray estimate that roughly two-thirds of the country could be considered immune to the Omicron variant, for now at least.

"We have changed," Ali Mokdad, a health metrics scientist at the University of Washington, told the Associated Press. "We have been exposed to this virus, and we know how to deal with it."