Two masks ARE better than one: CDC study shows a cloth covering over a surgical one blocks 92.5% of infectious particles - but officials are NOT recommending doubling up
US government researchers found that two masks are better than one in slowing coronavirus spread, but health officials stopped short of recommending that everyone double up.
The Centers for Disease Control and Prevention on Wednesday reported the results of a lab experiment that spaced two artificial heads six feet from each other and checked to see how many coronavirus-sized particles spewed by one were inhaled by the other.
They found that wearing two masks, like one cloth mask over a disposable surgical mask, can block up to 92.5 percent of infectious particles from escaping into the air.
But the CDC stopped short of recommending that Americans start doubling up their masks, and noted that other methods, like tying up the strings of a surgical mask can improve fit and efficacy.
'These experimental data reinforce CDC's prior guidance that everyone 2 years of age or older should wear a mask when in public and around others in the home not living with you,' said Dr Rochelle Walensky, CDC director.
'We continue to recommend that masks should have two or more layers, completely cover your nose and mouth, and fit snugly against your nose and the sides of your face.'
And President Biden's press secretary Jen Psaki said Tuesday that the White House is not advising it - despite Biden's own habit of wearing two masks - but is considering 'a range of options' to get face coverings to Americans.
A CDC report released Wednesday finds that wearing two masks can better than one, in protecting against coronavirus infection - but health officials are stopping short of recommending that everyone double-up, even though President Biden sometimes does
When both people double mask (middle, dark blue) or knot and tuck their surgical mask (bottom, dark blue), the experiment suggests as many infectious particles can be blocked as would be by a surgical mask
Her comments came after White House chief of staff Ron Klain said the Biden administration was considering an initiative to send masks to every American household - an plan first suggested by the Trump administration, but abandoned.
The White House now has 'a range of options under consideration on to how to ensure that people who need masks the most, people who need this type of protection the most, receive it, but no decision has been no final decision has been made,' Psaki said.
She added that the CDC's new report was not a formal recommendation, but additional findings that reiterate existing mask guidance.
'It doesn't actually issue definitive guidance on one mask versus two mask. Obviously if that's something they were to issue as official guidance, we listened to our health and medical experts,' Psaki said.
The CDC researchers found that wearing one mask - surgical or cloth - blocked around 40 percent of the particles coming toward the head that was breathing in.
When a cloth mask was worn on top of a surgical mask, about 80 percent were blocked from reaching the unmasked receiver.
When both the exhaling and inhaling heads were double-masked, more than 95 percent of the particles were blocked, said the CDC´s Dr John Brooks.
The researchers also found that knotting and folding a surgical mask to improve its fit to the face is about as effective as wearing a second cloth mask over it
Still, for now, health authorities acknowledge they have their hands full just trying to get more people to wear one mask and wear it correctly.
'The first challenge is to get as many as people as possible masking. And then for those that do mask, to help them get the best benefit out of that mask,' Brooks said.
Brooks said agency officials heard about people donning two masks and wanted to evaluate whether it was beneficial.
The study had many limitations: The researchers used one brand of surgical mask and one kind of cloth mask, and it's not clear if results would be the same with every product. But it echoes some earlier research that suggests two masks are better than one.
'It works,' Brooks said.
The CDC updated its guidance, saying people can wear a cloth mask on top of a disposable surgical mask 'for better fit and extra protection.'
If done correctly, the combination can tighten the gaps around the mask's edges that can let virus particles in, the CDC said.
The agency also said it will take down a make-your-own mask page, which went up last year when masks were in short supply and the CDC was encouraging people to take steps to interrupt viral transmission.
Some Americans have already started doubling up. Experts believe that's at least partly out of concern about new strains of coronavirus that have been found to spread more easily than the one that has driven the US epidemic for the past year.
Cases have declined by 15 percent in the past two weeks and new daily infections are down 57 percent from rates seen a month ago.
But more than 995,000 people tested positive Tuesday, more than 3,000 people died and the threat of more infectious variants that could dull vaccine efficacy looms.
CDC guidance has evolved over the course of the epidemic.
Mask-wearing has long been common in some countries during respiratory outbreaks, especially in parts of Asia, but not in the United States.
When the COVID-19 crisis began and masks disappeared from store shelves, US health officials actively discouraged the general public from wearing them.
'Seriously people - STOP BUYING MASKS!' then-Surgeon General Jerome Adams wrote in a tweet almost a year ago.
Two months later, after it became clear that infected people who did not exhibit symptoms could spread the virus, the CDC began recommending people wear masks in public.
Mask-wearing increased and some places enforced mask mandates, but many Americans continue not to wear them.
A recent University of California survey suggested that only about half of US adults wear masks when in close contact with people outside their household.
Discussions about double-masking and higher-quality masks are important, said Dr. Isaac Bogoch, an infectious diseases scientist at the University of Toronto.
'But if a significant proportion of your populations isn't wearing a mask in the first place, then you're having the wrong conversation,' he added.
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