Time to trash your mask? Not so fast

The US Centers for Disease Control and Prevention on Thursday announced that people who are fully vaccinated against Covid-19 may participate in activities indoors without wearing face masks or observing social distancing, even those in crowded settings. It had previously said vaccinated people could lose the mask when outdoors.

But don’t toss out your face mask and rush out on the town just yet. It’s not quite as simple as the CDC suggests. For one thing, its guidance is filled with exceptions. It doesn’t extend to buses, trains or planes. Or hospitals and nursing homes. Or prisons, or homeless shelters, or businesses that require face coverings, or . . . Moreover, this guidance does not supersede state and local orders. But the bigger complication is this: How do you know whether people have been fully vaccinated?

It’s not as if you can tell from looking at them. What you can be sure of is that the odds are good that most of the strangers passing through a public place, masked or not, are not fully vaccinated. Only about one-third of the population has been, which means they received their final shots more than two weeks ago.

This well-intentioned announcement is likely to confuse, and lead to more resistance to mask wearing among unvaccinated people, as well as put pressure on state and local health officials to drop mask mandates earlier than is wise. Science and data back up the CDC’s overall point that vaccinated people are in little danger if they hang out with unmasked and unvaccinated people indoors. Nevertheless, there’s still a risk of sparking new infections when you let unvaccinated and unmasked people mix.