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Data of the day: How long will different types of masks protect you from infection?

AP Photo/Andrew Harnik

Public attention has focused on the shortage of tests for understandable reasons but let’s please not ignore the bipartisan federal failure to get people wearing higher quality masks. There were excuses for that at the start of the pandemic, like the feds being caught off-guard by the virus and wanting to preserve the scant existing supply of N95s for health-care professionals. And it may be true (although I have no evidence to back this up) that cloth masks were more effective against previous strains of the virus than they are against Omicron, making the need for higher quality masks less urgent than it is now.

But even so, it’s a cinch that some vulnerable people have died because they relied on assurance from the experts that a cloth mask was sufficient to protect them from infection. How many fewer deaths would we have seen since March 2020 if the message from the start had been to wear a surgical mask at a minimum?

And to stress that nothing less than N95s would do for the old and immunocompromised?

Some authorities have been playing catch-up, shifting towards recommending or even requiring better masks to try to limit the spread of the hyper-contagious new variant. In Los Angeles County, businesses are now required to provide either N95s, KN95s, or surgical masks to employees who work indoors in close quarters with others. The same rule is in effect for students at USC:

The Mayo Clinic is also shifting to asking visitors to wear N95s or surgicals, and will supply a surgical mask to anyone on the premises in a cloth mask. How come? Why won’t cloth cut it anymore?

The WSJ points to this almost year-old data which I’d never seen before (or at least don’t remember seeing) to explain. Mask quality is often expressed in terms of particles filtered or percentages, which is hard for a layman to grasp. This table is much clearer:

Two points. First, because the data is nearly a year old, it pre-dates community spread of Omicron and even Delta. I’m skeptical that 2.5 hours of protection from a well-fitting N95 against a variant like Alpha would translate into the same amount of protection from the new variant, one of the most infectious known to man. No doubt a lot of Americans who’ve taken to wearing N95 have nonetheless been infected this past month.

But that goes to show why the pros are suddenly begging people to upgrade to N95s. That mask will at least give you a chance at avoiding infection. With a cloth mask, transmission of Omicron must take place in … what? Like eight seconds?

The second point is that you can see from that matrix why it’s important that everyone mask, that it’s not a pure matter of individual choice. You can protect yourself to some degree with an N95 or surgical even when you’re around an infected maskless person. But when everyone’s masking up, the amount of protection goes way, way up. Imagine how much we might have reduced the spread of Omicron if the public had been encouraged to switch to N95s months ago and the feds had made them freely available.

Zeynep Tufekci did imagine, actually. Are the feds still telling a version of the “noble lie” Fauci told at the start of the pandemic, when he claimed masks don’t work because he didn’t want the public snapping them up?

The C.D.C. still says that some N95s should be reserved for health care workers, even though they provide better protection for the wearer and the public than cloth or surgical masks, and even though there is no longer a shortage of them.

According to Walensky, N95s “are very hard to breathe in” and “are very hard to tolerate” so she worries that “if we suggest or require that people wear an N95, they won’t wear them all the time.”

Yet I’ve worn N95s many times, and there are many comfortable ones — some better than cloth masks because the seal is so good that my glasses don’t fog up. And if it were a problem, why hasn’t the C.D.C. made sure there were more comfortable ones available?

If you tell people “cloth masks don’t work against something crazily transmissible like Omicron, so upgrade,” they’ll upgrade. Walensky must know that, but she also knows that people in quarantine should be testing themselves before they stop isolating and yet she’s reluctant to say that too. How can you trust the CDC when they won’t plainly acknowledge best practices for health?

Tufekci asks another good question. Given the glut of counterfeit N95s and surgical masks on the market, why isn’t it easier for people to find guidance on which masks to buy and not to buy? The guidance is out there if you’re willing to Google around or dig through the CDC’s website, but I don’t think I’ve ever heard a federal official direct people to a database to help them buy stuff that’ll actually work. No wonder the average joe falls back on cloth masks. At least they know what they’re getting when they buy those.

Bottom line: Get some N95s from an established company (Honeywell, 3M, Kimberly-Clark) if you can afford it or else wear a surgical with a cloth mask over it. Anything less probably won’t help much amid the cloud of Omicron particles that’s descended on the entire country.