ARI SHAPIRO, HOST:
By the end of January, there may be 400,000 or more new cases of omicron each day in the United States. That's according to models from the University of Washington and the University of Texas at Austin. With numbers like that looming, many people are wondering whether we should change what we're doing to protect ourselves and others from this coronavirus variant during the holidays.
To offer guidance, NPR health correspondent Maria Godoy is here. Hi, Maria.
MARIA GODOY, BYLINE: Hi, Ari.
SHAPIRO: What's one thing people could do right now to better protect themselves and their loved ones?
GODOY: Well, beyond getting vaccinated and boosted, get a better mask. And by that, I mean a respirator like an N95, a KN95 or a KF94, which is a Korean standard. And the reason why is because omicron is so highly transmissible. It spreads at least three times faster than delta. So one person is infecting at least three others at a time on average based on data from other countries.
SHAPIRO: What does a respirator like an N95 mask do that a cloth or even surgical mask can't?
GODOY: Well, omicron really is different from previous variants in some pretty significant ways. One is there just might be a lot more of it in your respiratory tract. Here's Lindsey Marr. She's a researcher at Virginia Tech who studies how viruses transmit in the air.
LINSEY MARR: I've seen some reports that it replicates 70 times faster, maybe, in the respiratory tract. That would suggest to me that maybe we - it reaches higher levels and then we spew out more of them when - if we're infected.
GODOY: She says it's also possible we just need to breathe in fewer viral particles of omicron to get infected. But what is clear is that omicron is so contagious that a cloth mask is just not going to cut it right now. A respirator is made of a material that can capture more viral particles than cloth can. Surgical masks have this kind of material, too, but they fit looser and you need a snug fit, so no gaps for this variant. At a minimum, wear a surgical mask topped by a cloth mask.
SHAPIRO: In previous spikes, the guidance has been to wear one at, like, a grocery store, in a crowd outside. Do people need to wear a mask for something like a small family gathering over the holidays?
GODOY: You know, I asked Dr. Robert Wachter about that. He's the chair of the Department of Medicine at the University of California, San Francisco. And he says he will go unmasked in a small group of people if he knows everyone is fully vaccinated and boosted. And if they're not boosted, he says...
ROBERT WACHTER: I consider them to be somewhere between vaccinated and unvaccinated, and I act appropriately if I'm going to be around them. I either want to have masking, both of them and me, or I want to do rapid testing - one or the other.
SHAPIRO: Interesting that he brings in the rapid testing there. Is this a change in the guidance?
GODOY: Well, so before this winter surge, people were mostly using these at-home tests once they had symptoms. But the experts I talked to suggest using them as prevention. Rapid tests can tell you in the moment if you're infectious, which can be helpful if you're using them to figure out if it's OK to go see grandma that afternoon. So you take the test an hour or two before you head out. Abraar Karan as an infectious disease doctor at Stanford University.
ABRAAR KARAN: If they have a rapid test that's negative, that tells them that that day or for the several hours after that, the chance that they go and infect someone is very low.
GODOY: But he says to keep in mind the test cannot tell you if you'll be infectious the next day or the day after.
SHAPIRO: Of course, in many parts of the U.S., it's hard to find a rapid test right now. So if you've got a booster and a good mask and you avoid crowds, is that enough to just go forward with holiday plans?
GODOY: You have to do your own risk calculation, and it's really personal. For me, I might skip my tickets to "The Nutcracker" with my little girl tomorrow night because I plan to see my mom the next night, and I don't want to put her at risk.
SHAPIRO: I am sorry to hear that, but thank you for your reporting. NPR's Maria Godoy.
GODOY: My pleasure. Transcript provided by NPR, Copyright NPR.
