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Face masks effectively limit the probability of SARS-CoV-2 transmission

science.sciencemag.org

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Re: Face masks effectively limit the probability of SARS-CoV-2 transmission

#231

Post by unishark »

jonas21 wrote: post #199
Grimm665 wrote: post #184

Earlier quoted context omitted.

I haven't either but I did have to drive several miles out of my way a few months ago to get coffee filters at the only store in the state that seemed to have them in stock. I was told during checkout people were buying them in bulk to use as masks.

Or buying them in bulk... to make coffee? I'd assume that if people are working from home, they're also making coffee at home instead of getting it at work or on the way to work. And that would be a pretty reasonable explanation for shortages of filters that fit in home coffee makers. I know my personal use of coffee filters went up about 10x during the pandemic. And no, they were not on my face.

I would think a paper filter filters a lot better than cloth at least. The problem is breathing through it of course (as opposed to around). I searched and see some projects on the internet where people are trying to use them. Seems like a worthwhile idea to me.

Re: Face masks effectively limit the probability of SARS-CoV-2 transmission

#232

Post by [deleted] »

mattm wrote: post #153
function_seven wrote: post #113

Earlier quoted context omitted.

> On the other hand, "observational data show that regions or facilities with a higher percentage of the population wearing masks have better control of the coronavirus disease 2019 (COVID-19) (7–9)." So how to explain these contrasting results and apparent inconsistencies? My hypothesis regarding surgical mask prevalence and how it correlates with better virus control: People who wear masks--however effective they m…

"Some people with swine flu travelled on a plane from New York to China, and many fellow passengers got infected. Some researchers looked at whether passengers who wore masks throughout the flight stayed healthier. The answer was very much yes. They were able to track down 9 people who got sick on the flight and 32 who didn’t. 0% of the sick passengers wore masks, compared to 47% of the healthy passengers. Another wa…

[deleted]

Re: Face masks effectively limit the probability of SARS-CoV-2 transmission

#233

Post by unishark »

ekianjo wrote: post #77

So one can make a model out of thin air and not validate it, and then write a paper about it claiming to have the holy grail? That's Science in 2021?

Works best if it fits the bias/agenda of the journal editors. The better you do that, the more weaknesses they will forgive.

Re: Face masks effectively limit the probability of SARS-CoV-2 transmission

#234

Post by ixacto »

function_seven wrote: post #198
jasonlaramburu wrote: post #148

Earlier quoted context omitted.

It’s worth also considering the case of ski helmets. Since these have became common on the slopes head trauma has actually increased because wearers take more risks.

Yeah, or the idea that maybe helmets in gridiron football increase CTE. I see the possibility, but my own anecdotal experience with mask wearers and non-wearers jives with the other correlation: that non-wearers generally didn’t take the pandemic seriously. The people that I know who shunned masks also ignored the COVID threat in other ways: Large gatherings, vacations to another state to escape lockdown restrictions…

I wore a mask indoors. Then I got the vaccine. COVID is effectively over, unless we need booster shots this fall.

But feel free to wear a mask as much as you want, at this point it is effectively a security blanket though.

Re: Face masks effectively limit the probability of SARS-CoV-2 transmission

#235

Post by function_seven »

ixacto wrote: post #234
function_seven wrote: post #198

Earlier quoted context omitted.

Yeah, or the idea that maybe helmets in gridiron football increase CTE. I see the possibility, but my own anecdotal experience with mask wearers and non-wearers jives with the other correlation: that non-wearers generally didn’t take the pandemic seriously. The people that I know who shunned masks also ignored the COVID threat in other ways: Large gatherings, vacations to another state to escape lockdown restrictions…

I wore a mask indoors. Then I got the vaccine. COVID is effectively over, unless we need booster shots this fall. But feel free to wear a mask as much as you want, at this point it is effectively a security blanket though.

Same here. The only time I'm wearing a mask now is when the establishment asks me to. Otherwise, I'm back to normal.

Pre-vaccination, I was an indoor-only wearer.

Re: Face masks effectively limit the probability of SARS-CoV-2 transmission

#236

Post by irq11 »

mattm wrote: post #153
function_seven wrote: post #113

Earlier quoted context omitted.

> On the other hand, "observational data show that regions or facilities with a higher percentage of the population wearing masks have better control of the coronavirus disease 2019 (COVID-19) (7–9)." So how to explain these contrasting results and apparent inconsistencies? My hypothesis regarding surgical mask prevalence and how it correlates with better virus control: People who wear masks--however effective they m…

"Some people with swine flu travelled on a plane from New York to China, and many fellow passengers got infected. Some researchers looked at whether passengers who wore masks throughout the flight stayed healthier. The answer was very much yes. They were able to track down 9 people who got sick on the flight and 32 who didn’t. 0% of the sick passengers wore masks, compared to 47% of the healthy passengers. Another wa…

That is not “very much yes”, that is “an anecdote suggests yes”.

The statistical illiteracy here is astounding from professional scientists.

”0% of ths sick passengers wore masks, compared to 47% of the healthy passengers. Another way to look at that is that 0% of the mask wearers got sick, but 35% of non-wearers did”

And another way to look at it is that 65% of non-wearers didn’t get sick. The group of sick people is also quite small, meaning that the error bars on the effect size are large.

Sloppy, sloppy thinking.

Re: Face masks effectively limit the probability of SARS-CoV-2 transmission

#237

Post by alvah »

slver wrote: post #189
alvah wrote: post #142

Earlier quoted context omitted.

"even though the Chinese were very clear about it from very early on" I'm not sure this adds as much credibility as you seem to think. See (for example) - propaganda videos of people dropping dead in the street in Wuhan in early 2020.

Why on Earth are you calling them “propaganda” videos, when China was trying to downplay the pandemic at the time? See, this is one big reason we’re collectively dumb. Everyone and their big conspiracy theories.

There hasn't been a single case reported in the West, of anyone dying instantly in the street of COVID-19. Ergo, videos filmed within China, allowed by the authorities to be viewed outside China, purporting to show this scenario, are the very definition of propaganda.

Re: Face masks effectively limit the probability of SARS-CoV-2 transmission

#238

Post by nradov »

panarky wrote: post #229
__blockcipher__ wrote: post #163

Earlier quoted context omitted.

Except there is no convincing evidence that they actually do help others, and the whole theoretical mechanism is centered around catching large respiratory droplets which is at odd with the totality of evidence pointing towards aerosol being the dominant mode. I would add if droplet transmission is the dominant mode, which I very much doubt, then masks would still fail in a real-world setting when you look at the fac…

> no convincing evidence This MIT study [0] was pretty convincing. They conclude that "face masks can be an extremely effective indoor safety measure". For example: If an infected person was riding on a commercial airline with 100 other people, other passengers would be at risk of infection within 70 minutes. If all of the passengers wore masks, however, that space could be safe for up to 54 hours. [0] https://www.pn…

How can a model be convincing if it hasn't been extensively tested in the real world?

Re: Face masks effectively limit the probability of SARS-CoV-2 transmission

#239

Post by perryizgr8 »

panarky wrote: post #135
rsj_hn wrote: post #75

Earlier quoted context omitted.

Indeed this is the money paragraph: "The effectiveness of masks, however, is still under debate. Compared to N95/FFP2 respirators which have very low particle penetration rates (around ~5%), surgical and similar masks exhibit higher and more variable penetration rates (around ~30-70%) (2, 3). Given the large number of particles emitted upon respiration and especially upon sneezing or coughing (4), the number of respi…

> The effectiveness of masks, however, is still under debate Effective for the mask wearer, or effective for others in the vicinity of the mask wearer? It's well established that cheap cloth masks and procedure masks don't protect the mask wearer very much. The rationale for cheap masks is that they drastically reduce the spread of particles from the wearer to everyone else nearby . If your goal is to protect yoursel…

> then the cheap mask help a lot when people wear them.

Are there any reliable and conclusive studies supporting this?

Re: Face masks effectively limit the probability of SARS-CoV-2 transmission

#240

Post by Gibbon1 »

solarengineer wrote: post #176
mattm wrote: post #153

Earlier quoted context omitted.

"Some people with swine flu travelled on a plane from New York to China, and many fellow passengers got infected. Some researchers looked at whether passengers who wore masks throughout the flight stayed healthier. The answer was very much yes. They were able to track down 9 people who got sick on the flight and 32 who didn’t. 0% of the sick passengers wore masks, compared to 47% of the healthy passengers. Another wa…

What is astounding to a lot of us in South East Asia is the reluctance of the West in learning from our lessons. How many deaths and personal trauma experiences do people in general need to go through in order to learn from others?

Friends were talking about that a year ago. Health authorities in the west were completely ignoring their counterparts in Asia early on. Dismissed the threat until the pandemic blew up in Northern Italy and New York.

A lot of people in HN were arguing that the 0.7% fatality rate reported by Chinese authorities in Feb/20 was because Chinese medical care is bad.

Casual racism is kinda pernicious.

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