If you are vaccinated, boosted, and wearing a well-fitted N95 or similar indoors, “your risk is extremely low,” says Joseph Allen, a COVID and ventilation expert at Harvard. “I mean, there’s not much else in life that would have as low a risk as that. I would qualify your risk as de minimis.” An N95 mask filters about 95 percent of airborne particles. But two surgical masks—one on me, one on you—filter only about 91 percent, Allen wrote recently for The Washington Post. Because most people’s masks aren’t perfectly sealed onto their faces, studies show that N95s reduce the wearer’s uptake of coronavirus particles by 57 to 86 percent. And that’s on top of the protection that vaccines and boosters already offer.

Ideally, everyone would wear masks indoors for the next few weeks. That’s not going to happen, though. The good news is that if you’re boosted and wear a high-quality mask, you’ll probably be okay anyway. Some experts even think people who are triple-vaccinated and wearing N95s can go about their normal activities. “They should feel pretty safe because the booster provides strong protection against severe outcomes, and even if infected people are present and releasing viruses into the air, a properly fitting N95 will reduce the amount you breathe in by 95 percent or more,” says Linsey Marr, an environmental engineer at Virginia Tech who specializes in airborne transmission. “The combination of vaccination with [a] booster and an N95 provides excellent protection.”