https://www.vox.com/recode/2020/4/13/21214114/media-coronavi...

This advice was wrong. It is not just sick people that benefit from wearing masks. It is not true that people are flattening that into "masks don't work". Masks don't work was repeated many, many times by these organizations.

Here's an example:

https://www.cidrap.umn.edu/news-perspective/2020/04/commenta...

https://www.cnn.com/2020/03/30/world/coronavirus-who-masks-r...

https://www.businessinsider.com/who-no-need-for-healthy-peop...

Let's not practice revisionist history here. These organizations were dead wrong, and it had severe consequences for the spread of infection.

* There is no scientific evidence they are effective in reducing the risk of SARS-CoV-2 transmission

* Their use may result in those wearing the masks to relax other distancing efforts because they have a sense of protection

* We need to preserve the supply of surgical masks for at-risk healthcare workers.

It's a disease spread by exhaled droplets. How the heck could masks _not_ work? Why has common sense, as an acceptable way to obtain knowledge, died in the general public?

You're misrepresenting the entire problem.

The main unknown is not that protective equipment helps protect. That's a absurd strawman.

The main unknown is the impact on the likelihood that someone not educated or trained or experienced in facing biological hazards would contract a virus when knowingly exposing themselves to the virus while wearing said protective equipment to the best of their personal abilities, discipline, and knowledge.

That's the main unknown.

Meanwhile, do keep in mind that the effectiveness of condoms to stop unwanted pregnancies, which are pretty much widespread and even covered by classes included as part of mandatory public education, has been as low as 79% if poorly used.

https://www.webmd.com/sex/birth-control/birth-control-condom...

The main point is that face masks are known to not be full proof, and badly worn ones might even be less effective than not wearing anything as they provide incentives for people to repeatedly touch their faces. More importantly facemasks create a false sense of safety and thus invite unwitting people to needlessly expose themselves to the virus.

If you want to understand the problem, think of combat helmets. You can put one on and safely walk into a war zone, right?

The mask is not protecting you. It is protecting others from you.

If you were right, and wearing masks badly would have been worse than not wearing them at all (i.e. w.r.t. touching your face and all that), then countries that opted for mandatory mask wearing would be worse off and they aren't.

Related: https://www.preprints.org/manuscript/202004.0203/v1

> No one has studied masks on this specific strain? It's new for crying out loud.

Yes they have. Here's one where they take four patients who have covid-19 and fit them with masks and ask them to cough onto petri dishes. They find covid outside the masks.

https://www.acpjournals.org/doi/10.7326/M20-1342

>The median viral loads after coughs without a mask, with a surgical mask, and with a cotton mask were 2.56 log copies/mL, 2.42 log copies/mL, and 1.85 log copies/mL, respectively

My point was that if the statement read Scientific evidence shows masks are not effective it would means something. The lack of evidence showing effectiveness does not disprove effectiveness.

Yeah, maybe don't go around citing that one.

"This experiment did not include N95 masks and does not reflect the actual transmission of infection from patients with COVID-19 wearing different types of masks. We do not know whether masks shorten the travel distance of droplets during coughing. Further study is needed to recommend whether face masks decrease transmission of virus from asymptomatic individuals or those with suspected COVID-19 who are not coughing."

Obviously common sense will sometimes lead you astray. But it kept our ancestors alive long enough for us to be here, and it stops most of us from doing life-ending stupid shit every day. It's not a silver bullet, but nothing is, not even the scientific method. If you went looking for empirical peer-reviewed studies before making all your decisions, you'd never get anything done. "Should I poke my eyeball with this fork? Common sense says no, but fuck that shit. I better consult pubmed..." "Should I cough into Grandma's face, or into this handkerchief?"

You should really get some information on the topic you're discussing, because either you are oblivious to the point you're trying to argue against or are disingenuously misrepresenting what was actually and repeatedly said.

The main argument against wearing any protective equipment, including latex gloves which you casually omitted, was that a) it provided a false sense of safety that ironically ends up increasing the risk of contagion of everyone around you, b) create incentives for those wearing the gear to repeatedly touch their face with a much higher frequency, c) deplete the supply of protective equipment and thus deprive healthcare workers who directly contact with covid19 patients from having basic safety measures.

Evidence based medicine isn't there to stop crystal healing. It's there to work out whether knee arthroscopy is better than placebo. (For some patients it isn't).

Masks have a plausible mechanism of action. But they also have plausible mechanisms of harm: they may reduce social distancing; people touch their face more often when wearing a mask; most people don't know how to put on or take off the masks; most people don't have a safe place to store the mask when it's not being worn; etc. We don't know if the benefits outweigh the risk, because we don't have good quality evidence yet.

Here's some papers:

https://www.thelancet.com/journals/lancet/article/PIIS0140-6...

> Transmission of viruses was lower with physical distancing of 1 m or more, compared with a distance of less than 1 m (n=10 736, pooled adjusted odds ratio [aOR] 0·18, 95% CI 0·09 to 0·38; risk difference [RD] −10·2%, 95% CI −11·5 to −7·5; moderate certainty); protection was increased as distance was lengthened (change in relative risk [RR] 2·02 per m; pinteraction=0·041; moderate certainty). Face mask use could result in a large reduction in risk of infection (n=2647; aOR 0·15, 95% CI 0·07 to 0·34, RD −14·3%, −15·9 to −10·7; low certainty), with stronger associations with N95 or similar respirators compared with disposable surgical masks or similar (eg, reusable 12–16-layer cotton masks; pinteraction=0·090; posterior probability >95%, low certainty).

Here they say that distancing does work. But when talking about N95 masks they only say "could" work, and for cloth masks they say they have low certainty. Later in the paper they say they need more and better evidence for masks.

https://www.publish.csiro.au/hc/pdf/HC15950

Have a look at the table on page 2. They've looked at RCTs and they've found no benefit for masks. They go back and look at other data and they claim to find a benefit, which is why masks are recommended for HCPs.

When you say "it's transmitted by inhaled droplets" you didn't say how it's caught, and here it's clear that you think it's by breathing in those droplets. That's one route. The other is via the eye. Or the droplets land on surfaces and are transferred by hand to the eye or nose or mouth.

https://www.cmaj.ca/content/188/8/567

> Transmission of acute respiratory infections occurs primarily by contact and droplet routes, and accordingly, the use of a surgical mask, eye protection, gown and gloves should be considered appropriate personal protective equipment when providing routine care for a patient with a transmissible acute respiratory infection.

When someone coughs the droplets are expelled in a range of sizes. Some of these are trapped by cloth masks, but not all.

https://www.cidrap.umn.edu/news-perspective/2020/04/data-do-...

This statement is utterly absurd. The credibility of an entire scientific journal with nearly 200 years of operation is not shaken by accepting a scientific paper that after being subjected to peer review didn't held to scrutiny.

This line of critisicm reveals a profound ignorance regarding the whole scientific establishment. I mean, only someone entirely ignorant and oblivious to the whole scientific process would assume that passing the review stage of a scientific journal is a rubber-stamp of approval that all observations and ideas and conclusions represent the final and unquestionable proof. That's now how it works. Papers are published to expose ideas to peers and thus subject them to scrutiny. Some ideas don't pan out, some might be misguided, and there might even be some instances of straight pure scientific fraud. But that's not what the aim of the acceptance process, is it?

The upside of this sort of case is that suddenly we have random people caring about science and the scientific process. It's a shame though that they don't educate themselves on the very basics and instead are more interested in dragging institutions through the mud.

Retractions happen in all sorts of journals. Sadly, they will keep happening. Journals need to impose a page limit, alas a paper cannot describe its methodology down to every last detail, peer review can only do so much when you have bad actor intent on passing through.

This blip aside, it doesn't take away the fact NEJM and Lancet both have a history of being great sources of information, indeed they are still _the_ place doctors go to to get informed. I don't see that changing.

We're getting more information about specifically covid-19, and again that says that masks don't do much.

2. factually, several countries used masks as primary means of reducing transmission, including Czechs, Slovaks, Austrians, e.t.c. ... the sense of protection comes from seeing everybody else have mask

* clothmasks are enough, no need to stress about single-use disposable surgical masks

Now clearly your first and second points contradict each other.

Furthermore the absence of evidence is not the evidence of absence.

Cf. Peer reviewed studies, or lack thereof, supporting the 6 ft "social" distancing protocol and, up until recently, the use of parachutes while jumping out of a plane.

There's a big difference between a healthcare professional spending time in close contact with symptomatic people and a member of the public spending time walking round a supermarket.

And healthcare professionals do not "wear masks", they wear a full set of PPE including gloves, gown, mask, eye protection. They also have access to running water and soap, and alcohol hand gels.

> Peer reviewed studies, or lack thereof, supporting the 6 ft "social" distancing protocol

No, we have studies supporting 1 metre distancing and recommending 2 meter distancing. The evidence for this distancing is much stronger than the evidence for mask wearing.

Let's make our minds up about whether the lack of papers supporting mask-wearing against the virus is reason not to wear their them.

Also I'm earnestly interested in your source on the distancing evidence.

https://www.thelancet.com/journals/lancet/article/PIIS0140-6...

> 2019-nCoV transmission through the ocular surface must not be ignored

Source for distancing: https://www.thelancet.com/journals/lancet/article/PIIS0140-6...

Findings

Our search identified 172 observational studies across 16 countries and six continents, with no randomised controlled trials and 44 relevant comparative studies in health-care and non-health-care settings (n=25 697 patients). Transmission of viruses was lower with physical distancing of 1 m or more, compared with a distance of less than 1 m (n=10 736, pooled adjusted odds ratio [aOR] 0·18, 95% CI 0·09 to 0·38; risk difference [RD] −10·2%, 95% CI −11·5 to −7·5; moderate certainty); protection was increased as distance was lengthened (change in relative risk [RR] 2·02 per m; pinteraction=0·041; moderate certainty). Face mask use could result in a large reduction in risk of infection (n=2647; aOR 0·15, 95% CI 0·07 to 0·34, RD −14·3%, −15·9 to −10·7; low certainty), with stronger associations with N95 or similar respirators compared with disposable surgical masks or similar (eg, reusable 12–16-layer cotton masks; pinteraction=0·090; posterior probability >95%, low certainty). Eye protection also was associated with less infection (n=3713; aOR 0·22, 95% CI 0·12 to 0·39, RD −10·6%, 95% CI −12·5 to −7·7; low certainty). Unadjusted studies and subgroup and sensitivity analyses showed similar findings.

Interpretation

The findings of this systematic review and meta-analysis support physical distancing of 1 m or more and provide quantitative estimates for models and contact tracing to inform policy. Optimum use of face masks, respirators, and eye protection in public and health-care settings should be informed by these findings and contextual factors. Robust randomised trials are needed to better inform the evidence for these interventions, but this systematic appraisal of currently best available evidence might inform interim guidance.

Do hospitals get their stocks from hardware stores in boxes of ten? As much as I've seen, they buy from large distributors who prioritize government agencies and often don't serve individual consumers at all.

Some of you seem to think lying isn’t lying if your heart is pure, but it’s an ordinary word with an uncomplicated meaning.

  These organizations were dead wrong, and it had severe consequences for the spread of infection. 

Lot's of things are tried with a novel virus, and only some of them work. The only things so far that seem to be clearly working are distancing regulations and effective contract trace, the latter being very difficult to implement.

which masks? for what reasons?

> It is not true that people are flattening that into "masks don't work"...Here's an example:

This is an example... of how the advice got flattened. Quoting from that first link:

"Surgical masks likely have some utility as source control (meaning the wearer limits virus dispersal to another person)" "Respirators, though, are the only option that can ensure protection for frontline workers dealing with COVID-19 cases, once all of the strategies for optimizing respirator supply have been implemented."

See anything familiar from my earlier comment in there? Surgical masks are not personally protective, but they reduce transmission. Respirators are protective, but should not be general public resort.

The second article? It's talking about a global shortage, so it's clear which kind of masks they're recommending people not wear. Same with the last article... which also has a later section talking about how masks slow transmission and can be effective.

So... yeah. People were absolutely flattening the advice. And apparently some still are.

If you want, you can transform that into a communications argument, but like I said above, that reinforces the position that curation is an important part of the process.

Saying that "there's no evidence that masks work" is tantamount to saying they don't work. There is also no formal evidence that standing next to an infected person is a risk. I'm not aware of any studies that have officially proven that yet. But we still know that it is, and saying "there's no evidence that exposure to an infected person puts you at risk of infection" would be a ridiculously inaccurate thing to say.

"We do not recommend requiring the general public who do not have symptoms of COVID-19-like illness to routinely wear cloth or surgical masks because:

"There is no scientific evidence they are effective in reducing the risk of SARS-CoV-2 transmission

"Their use may result in those wearing the masks to relax other distancing efforts because they have a sense of protection

"We need to preserve the supply of surgical masks for at-risk healthcare workers.

"Sweeping mask recommendations—as many have proposed—will not reduce SARS-CoV-2 transmission, as evidenced by the widespread practice of wearing such masks in Hubei province, China, before and during its mass COVID-19 transmission experience earlier this year. Our review of relevant studies indicates that cloth masks will be ineffective at preventing SARS-CoV-2 transmission, whether worn as source control or as PPE.

"Surgical masks likely have some utility as source control (meaning the wearer limits virus dispersal to another person) from a symptomatic patient in a healthcare setting to stop the spread of large cough particles and limit the lateral dispersion of cough particles. They may also have very limited utility as source control or PPE in households."

Note the word in the first sentence: "requiring".

The article then goes on to describe filter fit and efficiency.

"These studies demonstrate that cloth or homemade masks will have very low filter efficiency (2% to 38%). Medical masks are made from a wide range of materials, and studies have found a wide range of filter efficiency (2% to 98%), with most exhibiting 30% to 50% efficiency.6-12"

"In sum, given the paucity of information about their performance as source control in real-world settings, along with the extremely low efficiency of cloth masks as filters and their poor fit, there is no evidence to support their use by the public or healthcare workers to control the emission of particles from the wearer."

As well as surgical masks...

"There is no evidence that surgical masks worn by healthcare workers are effective at limiting the emission of small particles or in preventing contamination of wounds during surgery.

"There is moderate evidence that surgical masks worn by patients in healthcare settings can lower the emission of large particles generated during coughing and limited evidence that small particle emission may also be reduced."

And N95 respirators...

"In summary, N95 FFRs on patients will not be effective and may not be appropriate, particularly if they have respiratory illness or other underlying health conditions. Given the current extreme shortages of respirators needed in healthcare, we do not recommend the use of N95 FFRs in public or household settings."

And in conclusion:

"While this is not an exhaustive review of masks and respirators as source control and PPE, we made our best effort to locate and review the most relevant studies of laboratory and real-world performance to inform our recommendations. Results from laboratory studies of filter and fit performance inform and support the findings in real-world settings.

"Cloth masks are ineffective as source control and PPE, surgical masks have some role to play in preventing emissions from infected patients, and respirators are the best choice for protecting healthcare and other frontline workers, but not recommended for source control. These recommendations apply to pandemic and non-pandemic situations.

"Leaving aside the fact that they are ineffective, telling the public to wear cloth or surgical masks could be interpreted by some to mean that people are safe to stop isolating at home. It's too late now for anything but stopping as much person-to-person interaction as possible.

"Masks may confuse that message and give people a false sense of security. If masks had been the solution in Asia, shouldn't they have stopped the pandemic before it spread elsewhere?"

All of this is backed up with a goodly stack of references. Which part do you consider dead wrong, and based on what?

> "There is no scientific evidence they are effective in reducing the risk of SARS-CoV-2 transmission

Given that the coronavirus appeared only a few months ago, "no scientific evidence" doesn't mean much because very little research exists on the subject. Also, there is no harm in caution.

Interestingly, they keep suggesting social distancing, which doesn't have much scientific support, either. It's just one of those common sense things.

We also have a lot of information about other respiratory viruses.

Repeated many times while they were stockpiling them for themselves to resell at 10x the cost to hospitals.

"Seriously people- STOP BUYING MASKS! They are NOT effective in preventing general public from catching #Coronavirus..."

"STOP BUYING MASKS" is not "Masks don't work," especially given the rest of the context of the statement where he's saying they're important to protect high-exposure roles healthcare providers. Which means he's also saying they work.

"They are not effective in preventing the general public" might be reasonably interpreted as "masks don't work", but given that he's clearly saying they work in the same breath, it's a better bet that he means something else.

It's clear that the message in the early stages of the pandemic was that "all masks didn't work, but you should save it for the health care workers". The absurd contradiction of that statement was what made reasonable people such as myself no longer trust what they said, because it was obvious they were hiding things from us. It's obvious that if you have a respiratory disease, then wearing a mask will be effective.

Since then, it has come out that masks are actually extremely effective in preventing spread.

No it hasn't. Show me the research.

> "all masks didn't work, but you should save it for the health care workers". The absurd contradiction

It's not an absurd contradiction. A member of the public walks around and is only going to meet a few people with covid-19, and hopefully they are pre-symptomatic (because if they have symptoms they need to stay at home)

A healthcare professional is stuck in a room with symptomatic people, often in close contact. And they're not wearing a cloth mask or fluid resistant surgical mask, they're wearing a mask that has to be fitted to them. They have training on how to put it on and take it off. They also wear gloves, a gown, and a face shield or eye protection. They have running water and soap, and they have alcohol handgel. For fluid resistant surgical masks they take them off and use a new one for each patient.

One patient in one ICU bay will have 30 pairs of gloves used by staff per day.

Here: https://www.livescience.com/face-masks-eye-protection-covid-...

> With face masks, the chance of infection or transmission was 3% with a mask compared with 17% without a mask, a reduction of more than 80%. And for eye protection, the chance of infection or transmission was 6% with protection and 16% without.

With someone in such an official position, misinformation can do great harm for people that know no better. Anyone who doesn't do their own research might think they're supposed to trust these people when worst comes to worst. And when they find out the advice is contradictory, that trust is lost, and might not be rebuilt for a very long time. It breeds doubt.

Personally however, I couldn't for the life of me believe that having no mask is better than having one.

But that reinforces the importance of well-curated communication, which is the context for this discussion, where apparently some are criticizing Amazon for refusing to release communication that is not only not-well expressed, as the tweet arguably is, but is actively disinformative to delusional.

https://www.snopes.com/fact-check/surgeon-general-against-ma... > One of the things [the general public] shouldn’t be doing is going out and buying masks … It has not been proven to be effective in preventing the spread of coronavirus amongst the general public … Folks who don’t know how to wear them properly tend to touch their faces a lot, and actually can increase the spread of coronavirus. You can increase your risk of getting it by wearing a mask if you are not a healthcare provider.

If you don't wear it on your face.

https://www.thelancet.com/journals/lancet/article/PIIS0140-6...

> The use of face masks was protective for both health-care workers and people in the community exposed to infection, with both the frequentist and Bayesian analyses lending support to face mask use irrespective of setting. Our unadjusted analyses might, at first impression, suggest use of face masks in the community setting to be less effective than in the health-care setting, but after accounting for differential N95 respirator use between health-care and non-health-care settings, we did not detect any striking differences in effectiveness of face mask use between settings. The credibility of effect-modification across settings was, therefore, low. Wearing face masks was also acceptable and feasible. Policy makers at all levels should, therefore, strive to address equity implications for groups with currently limited access to face masks and eye protection.

The onus is on the "they're dangerous!" folks now.

> However, the authors note that the findings on face masks and eye protection are based on limited evidence.

So limited that this finding was "low confidence". And that's for optimal use of N95 masks, not for fluid resistant surgical masks or cloth masks.

Here's what the actual study said:

> From a policy and public health perspective, current policies of at least 1 m physical distancing seem to be strongly associated with a large protective effect, and distances of 2 m could be more effective. These data could also facilitate harmonisation of the definition of exposed (eg, within 2 m), which has implications for contact tracing. The quantitative estimates provided here should inform disease-modelling studies, which are important for planning pandemic response efforts. Policy makers around the world should strive to promptly and adequately address equity implications for groups with currently limited access to face masks and eye protection. For health-care workers and administrators, our findings suggest that N95 respirators might be more strongly associated with protection from viral transmission than surgical masks. Both N95 and surgical masks have a stronger association with protection compared with single-layer masks. Eye protection might also add substantial protection. For the general public, evidence shows that physical distancing of more than 1 m is highly effective and that face masks are associated with protection, even in non-health-care settings, with either disposable surgical masks or reusable 12–16-layer cotton ones, although much of this evidence was on mask use within households and among contacts of cases. Eye protection is typically under considered and can be effective in community settings. However, no intervention, even when properly used, was associated with complete protection from infection. Other basic measures (eg, hand hygiene) are still needed in addition to physical distancing and use of face masks and eye protection.

Even the bit you're quoting says "face masks are associated with protection, even in non-health-care settings".

What's the control group?

Here's what the paper says about the evidence:

> Further high-quality research, including randomised trials of the optimum physical distance and the effectiveness of different types of masks in the general population and for health-care workers' protection, is urgently needed.

People who don't wear masks?

"We need more studies" is not the same as "our own study is bullshit". It's a simple statement of "there's something here that needs further confirmation".

In the meantime, I'm wearing a mask based on preliminary results, and the abject lack of "masks are actively dangerous" studies of any quality the anti-mask folks can refer to as a counterpoint.

There's no evidence that masks do anything at all to prevent public spread.

People point to countries that had successful anti-covid work and use of masks, but they're missing all the other work those countries did around social distancing and track and trace.

We even have the beginnings of evidence coming through for SARS-CoV-2. They got people who have covid to wear a mask and cough on a petri dish. Covid escaped the masks.

What? Medical personnel regularly utilize surgical masks against respiratory viruses spread by droplets successfully.

They're less useful against aerosolized stuff like measles, but SARS-CoV-2 is primarily spread via droplet.

[1] https://www.cnn.com/2020/03/02/health/surgeon-general-corona...

Just take all of your thoughts on digital books on Kindle, switch them to a collection of physical publishers who have a monopoly on printing presses, and ask yourself if you still think it's ok.

What if it's your opinion next time that is censored?

An Australian doctor discovered (about 20 years ago I believe) that a species of bacterium played a huge role in peptic ulcers. https://en.wikipedia.org/wiki/Barry_Marshall

He was censored, shunned from the medical establishment, and laughed at for years. He was correct.

Why do you place so much blind faith in these institutions to a point where you just KNOW it will never be you being censored? Are you a uniquely enlightened human being who has never had an idea that the majority of the people in the room completely disagreed with?

The medical establishment was censoring Barry Marshall because they were worried about the first and second order effects of people trying to treat ulcers with antibiotics. It was dangerous, they said.

How long before the guns get turned on you, me, or others?

The reason why was because he declared there existed something called "bacteria", invisible to the eye, which was infecting patients and killing them.

He was ridiculed (#fakenews!), stripped of his professional degrees, LOCKED IN AN INSANE ASYLUM and eventually, beaten to death by guards.

Well, turned out, ole Semmelweiss was onto something. Who knew?

https://twitter.com/Surgeon_General/status/12337257852839321...

Seriously people- STOP BUYING MASKS!

They are NOT effective in preventing general public from catching #Coronavirus, but if healthcare providers can’t get them to care for sick patients, it puts them and our communities at risk!

To me it looks like CDC/WHO hubris caused them to completely disregard Asia's approach until they could "discover" it themselves.

> * most masks provide marginal protection to the wearer

> * the masks that provide effective protection should be saved for those in situations where they need them (and can be knowledgeably used)

> * most people probably don't need those masks"

yup, moreover, masks are marginal on top of other measures, most notably distancing. masks can make a difference if you're in a situation where you can't distance when face-to-face in proximity of strangers for more than a short time. distancing requires less "expertise" and cognizance as well, so is a better principal measure all around.

that's a more nuanced message than "masks don't work". the opposing "wear masks at all times" is similarly dogmatic and incorrect.

You don't know that.

it's the distancing that's doing the work of "much less coronavirus". for your statement to be relatively true, we'd need to live in a world with no lockdowns and no distancing.

> The findings of this systematic review and meta-analysis support physical distancing of 1 m or more and provide quantitative estimates for models and contact tracing to inform policy. Optimum use of face masks, respirators, and eye protection in public and health-care settings should be informed by these findings and contextual factors. Robust randomised trials are needed to better inform the evidence for these interventions, but this systematic appraisal of currently best available evidence might inform interim guidance.

This is clear: physical distance definitely works. Optimal use of masks might work -- that's all they can say, and they need better evidence.

And I feel like we can reason about this to some extent from first principles - If the virus is spread through particles from faces, then face coverings will decrease the numbers of particles from faces that 1) get into the air and 2) get into peoples' faces, no matter how crappy the face coverings are. It seems more plausible to me that the problem is lack of data rather than incorrect conclusion, which seems like a reasonable interpretation of this particular study?