Cloth masks offer some protection against COVID-19, but surgical masks are better, experts say based on latest research
In recent months, some European airlines have banned the use of fabric face covers to control the spread of the coronavirus during air travel, favoring surgical masks and N95 respirators instead.
Cloth masks became all the rage when surgical masks and N95s were harder to find at the start of the pandemic. The federal Centers for Disease Control and Prevention still promotes fabric face coverings in their mask guidelines.
And masks remain an essential tool as people are mainly infected with COVID-19 by inhaling small aerosol particles that persist in the air or large respiratory droplets produced during coughing and sneezing.
But science is evolving. Delta, currently the main variant in the United States, is much more contagious than the original coronavirus, so the density of the virus in the air is greater.
As a result, some experts have adjusted their advice on masks.
âConsidering the Delta variant that exists, you probably need to upgrade your mask,â COVID expert and dean of the Brown University School of Public Health, Dr. Ashish Jha, told Fox News.
WHAT TYPE OF MASK TO WEAR?
Advice on masks has been mixed since the dawn of the pandemic. First of all, people were told that masking was not necessary. Soon after, that recommendation changed, but the public was advised against purchasing surgical masks due to the shortages. Instead, Americans have been urged to buy cloth masks or make their own.
Shortages don’t seem like such a big issue now, but the CDC still advises against choosing N95 respirators.
As recently as late August, the country’s top infectious disease doctor, Dr Anthony Fauci, declined to recommend better quality masks.
“Instead of worrying about the type of mask, just wear a mask”, Fauci said on MSNBC.
So what gives? Dr Peter Chin-Hong, an infectious disease expert at the University of California-San Francisco, said Fauci is taking a harm reduction approach.
âIt’s probably more important to wear something that you feel comfortable with, and that you can wear for long periods of time if you’re going into a particular environmentâ¦ rather than saying you have to wear the gold standard. at any time. Chin-Hong said.
Still, he said, âA baseline should be a surgical mask. ”
While Chin-Hong believes government and public health officials should focus on wearing surgical masks, he said cloth masks may provide sufficient protection under certain circumstances. He said a fully vaccinated person would likely get adequate protection from a cloth face covering for brief periods indoors when the venue is not at full capacity.
To help you decide, he suggests asking yourself:
- If you go inside, will the building be particularly crowded?
- How long will you be inside?
- Will everyone likely be masked?
- Are you and others around you fully immunized?
- Are you immunocompromised?
The riskier the situation, the more likely it is that a better quality mask is the best option, Chin-Hong said.
“Masks need to be beefed up to fight Delta, but that doesn’t mean those who can’t afford N95s have no options,” said Raina MacIntyre, head of the biosafety research program at the University. from New South Wales to Sydney, Australia, who has conducted many studies on masks.
MacIntyre said it was “possible to design a high performance cloth mask.” An experimental lab study she co-authored found that a layered fabric mask can effectively block droplets. The study, published in May in the journal ACS Biomaterials Science & Engineering, recommends using a minimum of three layers – a combination of cotton / linen and polyester / nylon – to resemble the droplet blocking performance of surgical masks.
Not only is layering important for improving filtration, it is too. One CDC-recommended technique for improving the fit of a surgical fabric or mask is to tie the straps and tuck the sides. A mask is generally suitable if you can feel warm air passing through the front of the mask as you inhale and exhale.
WHAT DOES THE RESEARCH SHOW?
A large-scale real-world study published this month found that surgical masks are particularly effective in reducing symptomatic infections. These types of masks have prevented one in three infections in people 60 years of age and older.
Researchers from Yale, Stanford and the nonprofit GreenVoice followed more than 340,000 adults in rural Bangladesh for at least eight weeks. About half received interventions such as the distribution and promotion of free masks. Villages that saw mask use drop from 13% to 42% and reported fewer confirmed COVID infections and a lower incidence of symptoms.
Villages where cloth masks were distributed reported an 8.5% reduction in symptoms. Villages that received surgical masks reported a 13.6% reduction.
When a third of adults with symptoms commonly associated with COVID agreed to have their blood tested for the virus, researchers found an 11% reduction among those who wore surgical masks. By comparison, they observed a 5% reduction in infections among those who wore fabric masks.
This study – conducted before the Delta variant circulated widely in the country – has not yet been peer reviewed, but some experts have already announced its methodology and results.
âWhen I saw these results, I threw off my cloth mask,â said Dr. Stephen Luby, study co-author and professor of infectious diseases at Stanford University. “If Delta is driving around and you’re going to wear a mask, why don’t you wear one that the data shows is good?”
âWe find very strong evidence that surgical masks are effective,â said Jason Abaluck, an economist at Yale who helped lead the study. âMy reading of this is that cloth masks are probably somewhat effective. They are probably better than nothing.
Abaluck suspects his study offers mixed evidence for sheet masks, as only about a third of those who reported symptoms consented to blood tests for COVID, so the sample size was too small to observe anything important.
âThe most likely interpretation of this whole constellation of results is that [cloth masks] really help, âAbaluck said. âIn fact, they make you less likely to catch COVID. This is why we have seen fewer symptoms.
Multiple observational studies and trend analyzes have found that community masking, which includes the use of fabric masks, reduces the spread of COVID. Study researchers in Bangladesh said there were drawbacks to these studies, which is why they conducted a randomized clinical trial. But they agreed with the overall assessment of those studies: People who wear masks are less likely to be infected than people who don’t.
âThis is the nature of science: science evolves,â said Luby. âWe have had proof that we get some protection from cloth masks. And now we have new evidence that we are getting better protection against surgical masks. “
KHN (Kaiser Health News) is a national newsroom that produces in-depth journalism on health issues.