Face Masks Really Do Matter. The Scientific Evidence Is Growing. New research suggests that face coverings help reduce the transmission of droplets, though some masks are more protective than others

Wall Street Journal ^ | July 18, 2020 | Caitlin McCabe

[karpov]

Face masks are emerging as one of the most powerful weapons to fight the novel coronavirus, with growing evidence that facial coverings help prevent transmission—even if an infected wearer is in close contact with others.

Robert Redfield, director of the Centers for Disease Control and Prevention, said he believes the pandemic could be brought under control over the next four to eight weeks if “we could get everybody to wear a mask right now.” His comments, made Tuesday with the Journal of the American Medical Association, followed an editorial he and others wrote there emphasizing “ample evidence” of asymptomatic spread and highlighting new studies showing how masks help reduce transmission.

The research Dr. Redfield cited included a newly published study suggesting that universal use of surgical masks helped reduce rates of confirmed Covid-19 infections among health-care workers at the Mass General Brigham health-care system in Massachusetts.

His comments are the clearest message yet from the CDC, amid fierce debate over facial coverings, fueled initially by shifting messages from federal and global officials about their necessity and then by those espousing individual liberties.

Researchers from around the world have found wearing even a basic cloth face covering is more effective in reducing the spread of Covid-19 than wearing nothing at all. And many are now examining the possibility that masks might offer some personal protection from the virus, despite initial thinking that they mostly protect others.

[TigersEye]

Yes, it’s hard ... even with just one. Kudos to you too.
For me it was the hardest thing I’ve ever done but also the best thing I’ve ever done.

Bad circumstances for me made it possible for me to be there and do it. I can’t be happy about those circumstances and yet I can’t not be glad that it created that opportunity.

More irony. Funny how things work out.

[mac_truck]

Yes or no, does the virus travel through the air by itself?

[jimnm]

Without getting into the mask effectiveness debate one way or the other, there are issues with this person's 'research'. Most of the citations he cited actually don't support his position. 2 of the 5 of the medical literature citations he selectively chose actually support the wearing of masks - both N95 and surgical masks in a health care setting - to protect the wearer from SARS (a coronavirus, covid-19 is SARS-CoV-2). The other 3 studies and literature reviews didn't look at SARS virus. So of the 2 he picked that did look at SARS, their findings supported the wearing of N95 and surgical masks by health care workers to prevent from getting infected by SARS. Worth pointing out that the physicist that wrote this was fired from his university 12 years ago after losing his marbles and blaming the Jews and the military-industrial complex for all of his problems. He apparently hasn't worked as a physicist since. He's into conspiracies and apparently didn't read what he was citing or he did and didn't report the issue that was actually relevant to what he was writing about (since he quoted from sentences directly before and after these SARS findings, but not the SARS findings themselves since they didn't support his position). None of these studies look at whether a mask is effective at blocking/reducing the distance of droplets that the wearer from spreads. This is what the WSJ article was about. I looked at the first 5 of his citations under 'Review of the Medical Literature' since these were the ones he said 'are key anchor points to the extensive scientific literature that establishes that wearing surgical masks and respirators (e.g., "N95") does not reduce the risk of contracting a verified illness.' 1st study is surgical mask versus no surgical mask at work (not coming to and from work on public transport in Japan). There were 2464 subject days and in each group there was 1 cold in the period (77 days). Nothing can really be drawn from that. An equally plausible explanation is that the two health care workers contracted a cold on the train or bus on the way to work, or out at the store, etc. 2nd study was a literature review and concerned influenza. The findings were mixed, some showed support for masks some didn't. Not clear cut. 3rd study definitely doesn't support his conclusions: One household trial found that mask wearing coupled with hand sanitiser use reduced secondary transmission of upper respiratory infection ⁄ influenza-like illness ⁄ laboratory-confirmed influenza compared with education; hand sanitiser alone resulted in no reduction. One hospital-based trial found a lower rate of clinical respiratory illness associated with non-fit-tested N95 respirator use compared with medical masks. Eight of nine retrospective observational studies found that mask and ⁄ or respirator use was independently associated with a reduced risk of severe acute respiratory syndrome (SARS). Coronavirus/COVID19 is a SARS-Cov-2 virus. That study says the opposite of what his conclusions are. According to this study, surgical masks and N95 masks protect the wearer against SARS, There was also a tendency to confuse N95 and surgical masks working equally well with the idea that meant that neither worked. This was an issue in some of the other studies as well. 5th citation: "Meta-analysis of observational studies provided evidence of a protective effect of masks (OR = 0.13; 95% CI: 0.03–0.62) and respirators (OR = 0.12; 95% CI: 0.06–0.26) against severe acute respiratory syndrome (SARS). " Coronavirus/COVID-19 is SARS-CoV-2. So 5th citation and 3rd citation both say that surgical masks and N95 masks offer the wearers of the masks protection against SARS. Coronavirus/COVID19 is SARS-CoV-2. He didn't draw attention to this because it undermines his conclusions.

[gas_dr]

You like to play gotcha — it is obvious. Trying to have this conversation with you is like educating a 3rd grader on calculus — please go educate yourself. There is a lot of reading for you to do and then you can be proud that you have an answer based on text book and scientific process, not Dr. google

I know the answer after years of advanced study and practice. Go educate yourself.

[backwoods-engineer]

Won’t comply. Too many lies, too many obviously mendacious predictions that never panned out, and a clear Satanic connotation. Jesus will judge all who are part of this worldwide diabolical deception.

[hadaclueonce]

I’m writing political statements on mine.
I don’t use PC or very nice words.

[thecodont]

So I had the weirdest experience this week.

I had just parked my car, in my own space, and gotten out. I had my mask in one hand, and a bag of tools in the other, when this guy, across the street, 30 feet away, starts yelling at me to “put your mask on”.

I should have been kinder. I could have been kinder. But somehow, some of the frustration with these morons leaked out, and I found that my command of certain pithy Anglo-Saxon words was undiminished. I think I might just have made my old DI proud, bless his crusty heart.

Dude actually called the cops, ?!!!?

and I was so entertained that I waited for them. They were chill, and rolled their eyes when they explained to the poor sod that even in Cali, there is no mask mandate out of doors “unless it’s impossible to maintain 6’ of social distance”.

Nice to hear that the cops were chill and reasonable.

People are on edge though, and I’ve resolved to try to be better if/when a similar opportunity arises in the future.

Thank you for sharing that.

I think people are very, very afraid of being written up by law enforcement if they are bare-faced even a centimeter closer from someone than the local ordinance of the day says they should be.

Yes, people are on edge. You are very right. Everyone wants to see the light at the end of the tunnel. everyone wants to see freedom returned, and then there's the gov't announcing another restriction, another rollback, another closure.

It's breaking people's hearts.

With these stupid masks on, we can't even smile at each other anymore. How sad is that?

[dynoman]

"A COVID-19 (SARS-CoV-2) particle is 0.125 micrometers (μm); influenza virus size is 0.08 – 0.12 μm"

"Virus-laden small (<5 μm) aerosolized droplets can remain in the air for at least 3 hours and travel long distances."

"All of the cloth masks and materials had near zero efficiency at 0.3 µm, a particle size that easily penetrates into the lungs."

"Conclusion: Wearing masks will not reduce SARS-CoV-2."

"Cloth masks will be ineffective at preventing SARS-CoV-2 transmission, whether worn as source control or as personal protective equipment (PPE)."

https://aapsonline.org/mask-facts/?fbclid=IwAR3lQATLfcS1LTQ8UbZAarOHnKk0qdzSkYNvy1Z3ohGtXrpoRghwfMgF3yY

[LegendHasIt]

The brightest point for me was that my father and I barely tolerated each other until the last few years, and we managed to ‘part as friends’.

[freeandfreezing]

The interaction between the incubation period and the typical lag from incubation to a confirmed positive report results in a lag in data representing infections relative to the actual time when the infection occurred.

Correcting for this aspect of the data seems to be something that is often overlooked in recent research. I don't see from a quick review of the JAMA article that they considered that aspect of the data. The effect of the time delays can be seen in the more detailed modeling and analysis presented by the R(t) research team. Their data and analysis for Massachusetts, available here seems to suggest that the overall rate of infections peaked on April 1st in Massachusetts. I would expect that the peak for health workers might ordinarily lag that of the general population since they have a risk both from their general exposure and a higher risk from at work exposure to COVID-19 patients. The latter risk arrives a few days after the patients themselves became infected, as you noted.

Common sense tells us using masks in a hospital setting is a good idea. I would hope that we might see reductions in all airborne diseases among hospital patients as a result. But separating the effect of mask wearing from, for example, next to no contact with other people outside of the hospital is very difficult statistically.

[lilypad]

NewMexico has had the strictest rules and the cases are still rising so the governor doubled down and made it mandatory to wear a mask when exercising, jogging, riding a bike,etc.

[freeandfreezing]

Here is an article you can read to start to educate yourself on the difficulty of preventing viral infection by using masks. More than 20% of the nurses in the study exposed to influenza, a virus similar in size to the COVID-19 virus for purposes of mask efficacy, were infected regardless of whether they used a surgical mask or an N-95 respirator.

So for a similar virus, when exposed to influenza, the N-95 respirator is less than 1% better than the surgical mask, and both fail more than 20% of the time. They help, since perhaps the unmasked nurse would have been at even higher risk, but the study did not test that hypothesis.

[freeandfreezing]

That's a dumb question. At one level the answer is yes, of course it does like any other particle of the same size. At a more useful level the question is does the virus tend to be expelled in sufficient quantities and survive in the air long enough, and end up in sufficient concentrations to be infectious. And the answer to that, from published research, seems to be yes, in some circumstances. What is apparently not well known is the distribution of droplet sizes carrying significant viral loads generated by people and how fast they disperse, drop to the ground, or otherwise become non-infectious.

Some data suggests that people singing or talking loudly in crowds generate the type and number of droplets that can cause transmission in interior spaces.

[dforest]

Blow it out you left ear. What a bunch of malarky you just posted. I am still laughing.

[mac_truck]

Lol...I think we both know the answer to the question ask you.

No need to gaslight, doctor.

[rockrr]

I hope you didn’t have to wait long for the cops to arrive.

You’re absolutely right - people are on edge. I’d say that more than 50% are currently certifiable right now. And it ain’t getting any better!

[rockrr]

“Masks make you stupid”

/s

[gas_dr]

My apologies, please forgive.

[TigersEye]

Is that really sarcasm? Lowering blood O2 levels and increasing CO2 levels will absolutely lower a person’s cognitive abilities. :)

[moovova]

Is this the same CDC that Trump has bypassed with test results?