Over the last three months of the Coronavirus pandemic it has become remarkably clear what the biggest government failure was. It wasn’t the lockdowns. It wasn’t the lack of PPE and other medical equipment. It wasn’t even the faulty test kits and testing restrictions. It was discouraging people from wearing masks. Officials said they wouldn’t be effective for the common person. Maybe they were trying to preserve masks for hospital staff—but in that case they should’ve just been straightforward with the public. Or—as I would guess- they were just very wrong. Regardless, it has become increasingly clear that masks are very effective at limiting the spread of the virus. The evidence is piling up. Here is what we know.
First, why are masks important? Masks can be effective through two means. First, they limit the number of respiratory droplets from an infected person from getting into the air and infecting another person. Second, they limit the number of respiratory droplets someone breathes in. When mask opponents criticize mask wearing they often focus on the second reason. While it is the weaker of the reasons, it’s also looking increasingly valid.
A recent study by infectious disease experts at Hong Kong University shows just how powerful mask wearing can be. The study ran a simple experiment: have two groups of mice– one infected with COVID-19 and one healthy. Have a fan blow air from the infected group into the healthy group. Run this experiment with no mask barrier, with a mask barrier over the infected, and a mask barrier over the healthy. The COVID-19 infection rate went from 67% in mice without any mask barrier to 17% in mice with a mask barrier over the infected– a 75% drop! And in mice with a mask over the healthy group the infection rate was 33% — a 50% drop!
Another study— this time from the CDC– took a retrospective look at the USS Roosevelt outbreak– the aircraft carrier that had a COVID-19 outbreak while at sea. Turns out the most effective strategy for reducing infections was wearing a mask! 80% of sailors who didn’t wear a mask tested positive for COVID-19 while only 55% of sailors who wore a mask tested positive. Wearing a mask for personal protection reduced COVID-19 infections by about 33%. And that was in a contained environment with tons of unavoidable close contact. That’s huge!
Given those two studies, it’s clear masks reduce the virus’ spread. Take two hair stylists in Missouri. Combined they served 180 customers while infected. Yet, there were zero infections. How? Because both put up with the slight discomfort of wearing a mask.
Or take Hong Kong. 7.5 million people live in the city. With 17,552 people per square mile. The city is extremely dense. Yet, there are only 1,108 confirmed cases and only 4 reported deaths. New York City, on the other hand, has over 200,000 confirmed cases and over 17,000 reported deaths. While NYC is slightly more populous and dense the gap is nowhere near large enough to explain the different COVID-19 experiences. But mask wearing does. Like many other places in Asia, mask wearing in response to infectious diseases is a part of the culture.
In lieu of a conclusion, I’ll leave you with three other interesting findings from the CDC study. First, extra hand-washing had a very small effect. Second, social distancing and avoiding crowds both had a clear effect. Lastly, the study suggests herd immunity is around 80%. That means if the US would go for herd immunity, well over a million people would die.
Exit quote: “You cite a paper, a scientific paper that found that if a majority of people wore masks, this pandemic could end.” – Mary Kelly, NPR
“That’s right. You need at least 60- to 75% of us wearing a mask, which means we don’t have to be 100%. And the second thing is we’ve got to be wearing masks that are at least 60- to 75% effective. It needs to be at least a double-layer cloth mask or a proper surgical mask like people wear in the medical world. And it has to fit reasonably well.” -Dr. Atul Gawande