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Reducing transmission of SARS-CoV-2 (science.sciencemag.org)
62 points by sohkamyung on May 28, 2020 | hide | past | favorite | 53 comments



The problem is the scientific community did not immediately denounce those scientists that clearly were putting policy before science.

It wasn't just the masks saga. Anyone with basic comprehension of physics and particle data can see how and why masks work, so Don't try to fool the public by lying and don't sit by when some colleagues are basically destroying the whole of the scientific community's credibility just to appease some political interests.

Same for 'social distancing' in enclosed spaces. If you let that sort of nonsense stand, how can you not realize you are just throwing the whole of the scientific trust under the bus?

And now the latest one: 'Children do not transmit the virus' just because some political parties want to reopen schools ASAP?

Just stick to the science, and leave the politics to the politicians.

As I said here back in March, the damage done to scientific credibility is the most saddening collateral in all of this. There wil always be some persons willing to do someone's dirty laundry for fame, gain or even just because they genuinly believed it all 'white lies' for the best of intentions. The huge failure of the scientific community was not calling them out.


> The problem is the scientific community did not immediately denounce those scientists that clearly were putting policy before science.

Who said this though? This seems like a caricature. All I remember is a bunch of confusing messaging from the WHO and a bunch of tut-tutting from experts warning people not to hoard or stockpile PPE that was needed more pressingly by health care workers.

Can you be specific about who said what, and when, that "destroyed the whole of the scientific community's credibility"? I just don't see it. In my world by late march everyone was wearing homespun masks form Etsy...


What is your evidence that children actually do transmit the virus efficiently?

I have seen multiple independent studies from different countries coming down with a very similar conclusion that children are not good vectors for this thing to spread.


> What is your evidence that children actually do transmit the virus efficiently?

OP's point is about if children transmit the virus. Either they do or don't.

But your question is about the efficiency of how children transmit the virus. It's an entirely different question although your personal choice of weasel words makes it look differently.

It makes no sense to waste time talking about efficiency if you're talking about a known virus transmission vector.


By that measure masks do not work since N95 allows a certain level of particles to transit. Perfection is not necessary, only reducing the replication factor.


> By that measure masks do not work

That's a stupid remark. N95 are used mainly to reduce the emission of our own droplets, not to eliminate it nor to make us invulnerable.

Still, the recommended approach is still to stay at home and avoid contact altogether. As it's obvious to anyone, no exposure is far better than some exposure.


Fair point.

Please now explain how reopening the schools will reduce the replication factor.


Science is science and policy is policy. In the end, if you want science to be useful, you have to recommend a policy, and scientists can do that, too. You just have to be clear on what is scientific results and what is policy recommendations based on said results.


How many steps of the scientific method should scientists need to get through before they can make policy? Throughout this pandemic we've been getting whipsawed by "science". Is a few months really enough time to do all the science on a question as difficult as the efficacy of masks during a novel virus pandemic?


Masks are prudent, considering that they are a very low risk and low cost prevention intervention, irrespective of demonstrating efficacy.

True, it takes a long time (often very long) to establish factual information that becomes widely accepted, but that is not the issue here. Also, the scientific method and peer-review process cannot be altered, and these processes (along with always following a strict code of ethics, staying updated on ethical matters, never compromising on ethics, and never losing sight of all of the above—ever) are even more important during a pandemic. Implying that these processes should be altered is unethical and unconscionable.

We have known that SARS-CoV-2 spreads via respiratory droplets, and that it was, most likely, by far, the main mode of transmission (although that would have needed to be demonstrated too, in a pandemic). Wearing a face mask to capture some of those respiratory droplets (even 10%) would at least help, and would not be insignificant if people are required to wear them in public.

We know that cloth masks capture more than that though.

Also, based on a case report, it is possible that up to 80% of COVID-19 infections are asymptomatic.

Considering that, and the fact that it is spread mainly by respiratory droplets, it is prudent to require the public to wear at least cloth masks.

Czech Republic (along with Slovak Republic—Slovakia) required people to wear face masks in public starting around March 13, and was one of the first western countries to require this. They are now easing restrictions and are doing well.

One of the countries I am sovereign to, Croatia, (US is the other one) has not had any reported coronavirus infections for 3 days in a row. You know, a former war-torn Yugoslav country, still feeling the after effects, with a relatively high and rapidly accelerating quality of life, by western standards.

Stuff like mask wearing is not rocket science.


Finally. What was obvious from the Diamond Princess data months ago has been acknowledged.


Can you be more specific on what you think was going unacknowledged? The abstract is just "wear masks and test like crazy". Which has been pretty much universal consensus since March. There's a whole industry of amateur mask makers on Etsy at this point.


It depends on the region. This sort of study is still greatly needed in places. Like Australia, where the official statement is: "Surgical masks in the community are only helpful in preventing people who have coronavirus disease from spreading it to others. If you are well, you do not need to wear a surgical mask as there is little evidence supporting the widespread use of surgical masks in healthy people to prevent transmission in public" [ https://www.health.gov.au/resources/publications/coronavirus... ]

Check out Australian news sites to see all the maskless people.


Until recently wearing masks Was not a CDC guideline


No one at the CDC (at least no career bureaucrat) ever denied masks were effective, though. It's true that there was concern early on that a public run on masks would put health care workers in jeopardy, so people were absolutely told not to try to procure them. And it's also true that the WHO's messaging on this subject was terribly confusing.

But the idea that "Hah! The elites were WRONG about masks!" is just... weird. And doubly so because it's almost always promulgated by a demographic known for... not wearing masks.

I mean, seriously: if ("finally!") we're being told to wear masks, I'd expect a genuine mask evangelist to be happy, and to use this to encourage others to wear their masks. But that's not what I hear. It's like it's all a game of political gotcha.

It's not. Masks save lives. Wear your mask when you can't stay home.


I’m based in Tokyo and one of the most frustrating things for me personally is that ~90% of foreigners (or people who are visibly foreigners) are not wearing masks when out and about. This despite the fact that the Japanese are almost uniformly wearing them. We are, after all, in the middle of a pandemic.

Is this down to the WHO’s early messaging fumbles, misplaced machismo, ignorance, or what? When foreigners here don’t wear masks, they should know that the door is then open for Japanese people to lump all of us in together and say: “look, foreigners don’t give a fuck.”


All of the people I've discussed it with say that they think masks are dehumanizing. I suspect that there's an association with criminality too.


Ironic, since it's even more dehumanizing to blithely expose another human to a potentially fatal virus.


> No one at the CDC (at least no career bureaucrat) ever denied masks were effective, though.

Not the CDC, but the U.S. surgeon general, Feb 29th: "Seriously people- STOP BUYING MASKS! They are NOT effective in preventing general public from catching #Coronavirus"

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

Once more data came in proving the effectiveness of masks, he acknowledged in a later tweet that this is incorrect, and encouraged mask usage. But that doesn't change the fact that there was a high-level denial of mask effectiveness.

P.S. I am in fact a mask evangelist, and I don't understand why anyone would avoid them given the data.


"They are NOT effective in preventing general public from catching #Coronavirus"

This statement (my emphasis) is, as far as I know, still correct, because masks are only effective if fitted properly and people are trained to use them correctly (like absolutely no touching of the mask.)

What's changed (at least in the US) is that early on the focus was on people hoarding surgical masks because they thought it would prevent them from getting infected, in the presence of a widespread shortage.

Lately, the focus has been on the benefit of mask use as a means of reducing transmission of the virus, where the evidence points to mask use being uniformly beneficial and the concerns about mask touching etc don't apply since the assumption is that you may already be infected.

This is also what the "mask protesters" don't seem to understand (or ignore.) They talk about wearing a mask or not as a personal risk decision, when it's actually about whether you expose others to the virus.


It seems like a lack of imagination to not instead suggest cloth masks if they wanted to avoid a run on n95s.

Meanwhile, you still see people wearing valved n95s, which I'm to understand are less effective in preventing transmission from the wearer (https://www.sfchronicle.com/bayarea/article/Coronavirus-Bay-... ). I saw that surgeon general tweet dozens of times from tut-tut types on social media at the onset of lockdown, but info on valved n95s is buried in a cdc faq: https://www.cdc.gov/coronavirus/2019-ncov/hcp/respirator-use...


Read an article on Mongolia of all places. Instead of insanely lying that masks weren't effective they just out and out told people that they needed to reserve N95 masks for hospitals and then deployed an army of (likely mostly) women to sew standard cloth masks.


[flagged]


> subways, nursing homes, masks, the relative safety of being outdoors, etc.

OK... go through that then? All that stuff seems like areas that have been broadly agreed upon for months. You're going all the way back to March for a bunch of recriminations (some of which I don't understand -- nursing homes were early hot spots and have always been seen so). No one doubts that people got stuff wrong. But that's not a reason to argue against the same people now that they've corrected themselves.

I mean... you ARE wearing a mask, right? Right?


Except that everyone stopped wearing masks about two weeks ago.


For certain narrow classes of everyone.


In the part of America I live, you cannot enter buildings or public spaces without a mask. Not everyone has the same policies.


That is one of the stupidest graphics I have ever seen in an academic journal article.


> For society to resume, measures designed to reduce aerosol transmission must be implemented

This is an opinion piece disguised as science. It’s presumptuous of a science writer to make determinations about whether and how society will be permitted to resume.

If we want people to be perfectly safe we’d also ban fast food, meat, alcohol, nicotine, driving and sex. But the goal of society is not to keep people 100% safe. Why are we okay with having our liberties trampled over an illness that the CDC estimates has a 0.26% death rate?


Because the death rate is way higher than 0.26%. If the CDC really thinks it's that low for the general population then they are wrong. The general consensus I have seen, based on antibody tests in New York, Italy, Sweden, and Spain point to a death rate between 0.75% and 1.25% for most developed nations. For less developed nations (which, to be fair, is most of the world) the death rate will be lower because there are fewer old people. I agree that we don't have to shut down everything, but everyone should be wearing masks as much as possible in public. Public smoking is highly restricted, at least partially because of the risks of secondhand smoke, and the risks of COVID-19 are way higher than that. People can do what they want at home, but we have to share public spaces. It's not right for someone else to make decisions that endanger me and my family just because they don't care about the risk.


Comparing deaths from previous years for the same month(s) (of the pandemic), along with the expected number of deaths (projected) for 2020, is how this sort of calculation is made, on a preliminary basis.

There is an (older) Financial Times article that did an excellent analysis on this (free to read): https://www.ft.com/content/a26fbf7e-48f8-11ea-aeb3-955839e06...

But, this article (also free to read) came out today from the Financial Times and is way better. The UK is doing far worse than the US interestingly: https://www.ft.com/content/6b4c784e-c259-4ca4-9a82-648ffde71...

Countries like France, Spain, and Italy (Mediterranean countries) in particular rank badly (besides having an uncontrollable infection problem) for the calculation of total excess deaths (compared to previous years) because they have some of the highest average lifespans in the world, largest percentages of elderly populations, and have extremely high quality universal healthcare (for example, the third leading cause of death in the US is actually preventable medical errors, so we really do not have phenomenal healthcare, even if you have “great insurance” and “can pay for it”).


The CDC latest best estimate is 0.4% death rate from Covid. This compares to a death rate from the flu of around 0.2%, also based on CDC estimates [1].

Every death is a tragedy, but we didn't do half-lockdowns for the flu before. Why are we doing a full lockdown for something that is 2x the flu.

Antibody testing largely supports a 0.4% death rates conclusion, I've tracked this data in a spreadsheet I made [2]. 0.4% is close to the mean and median of the studies I recorded.

Edit: I know it's gauche to complain about downvotes, but this post is just citing data to make a point. Even if you are worried about Covid, it seems dishonest to downvote data.

[1] https://www.wcnc.com/article/news/health/coronavirus/data-cd...

[2] https://docs.google.com/spreadsheets/d/16onEUBWIV5IqN1RCvTla...


Another point of caution here is that CDC adjusts flu mortality rates for under-reporting in an attempt to estimate how many people actually died of the flu, as opposed to how many people have influenza listed on their death certificates.

COVID-19 mortality rates, however, are almost always reported according to narrower inclusion criteria (either positive COVID-19 dx or "presumptive COVID-19"), so there is a risk of an apples-to-oranges comparison here. One ought either count death certificates or estimate the total mortality burden, but not both.


I've looked into this a little bit, actually.

There are two parts of flu/covid IFR: fatalities and infections.

For flu fatalities, the CDC does indeed upward adjust the count. They do this by looking at how many people died of pneumonia, and multiplying that by a number. The number is the estimated percent of pneumonia deaths that are from the flu, which they base on historical data.

For flu infections, it's a bit more obtuse. The best I was able to find was this paper from the CDC [1], which says they use a Monte Carlo model to estimate the number of infections.

For Covid, the deaths are based on diagnoses, not necessarily tests. Diagnoses are from symptoms, so it is not completely accurate. Some flu cases could be misdiagnosed as covid cases if you don't do a test. For infections, the numbers are typically based on the results from antibody tests (not Monte Carlo models).

I agree that it's definitely not apples-to-apples comparison, but it's hard to say if the comparison is in favor of flu being more deadly, or covid being more deadly, because there are confounding factors in both directions.

[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4603749/


Thank you for putting that together. Is there a git repo for covid-19.direct or similar?


Yep, the repo is at https://github.com/xunhuang/covid-19 . I didn’t write it, but the maintainer is fairly responsive to pull requests and issues.


While I personally also think that the lockdown and movement restrictions have been excessive, it's not especially helpful to compare this new coronavirus to the flu, because people can significantly reduce their risk of catching the flu by getting a vaccination. Lockdown is a strategy put in place not because of the increased mortality rate, but because the "standard" risk mitigation of vaccination is not available for this virus.


I genuinely mean this with no disrespect but how knowledgeable are you about this & if you aren't why do you think some data collecting from the internet & "back of the envelope" spreadsheet-ing makes you able to reasonably question world experts that dedicated their careers to virology and pandemics?

If you are a programmer how much would you appreciate a medical doctor with no training or experience in software development questioning your technical decisions about what to use when building a software service?


Probably because it's hard to trust public health experts in a crisis whose very existence has already demonstrated a failure in their authority.

If I wanted to reduce the risk of acquiring or transmitting an airborne infection back in February, I would wear a mask and avoid enclosed spaces without waiting for CDC's permission. Indeed, I would ignore their advice to the contrary, which stood until April (!)

It would be really nice if we could defer to competent technocratic experts, but they earn their trust by having credible track records, not by collecting credentials.


No thanks. The Hippocratic oath is meaningless unless the subject decides what constutites a medical procedure.

The train to technocratic ditatorship is paved with... the great glucose poisioning epidemic, loss of free speech, loss of self defense. Todays conventional wisdom is often not looked on favorably in the future.

http://www.youtube.com/watch?v=TRnB9El_V5g

Are we going to wear masks for the rest of our lives (outside FFS)? Pandemics are an authortarian dream. The ability to engineer pandemics will only expand.

A bit of scale: Consider how many children go missing in the US each year.


As far as I can see the main screw up was the American and British governments ignoring expert advice. I live in Germany which happens to have a responsible adult in charge & this country fared great in this crisis so far.


The 0.4% fatality estimate is from the CDC, presumably full of credentialed experts. My spreadsheet is a collection of studies from experts who have presumably dedicated their careers to virology and pandemics. The 0.2% number is also from the CDC. I’m not out there doing science, I’m just looking at the data.

I’m not sure what the basis is if your criticism. If a medical doctor wants to submit a PR I would review it based on merits.


It looks like your spreadsheet divides deaths on a given date by (confirmed and estimated) cases on that same date? This will bias your estimate downward. There is a significant lag between diagnosis and death (and even more so between infection and death -- which of these is relevant depends on how you are estimating unreported cases), but you're implicitly assuming that 100% of unresolved cases will end in recovery.


You are correct, deaths lag a bit, as does reporting of the deaths, which downward biases the IFR. Antibodies also lag before they show up in the serology tests, which upward biases the IFR.

But broadly, the studies I've cited largely back up the CDC's estimate of 0.4% IFR. Some of them have methodology in the papers themselves which give similar numbers, and I encourage you to read the raw data.

But an IFR close to the flu is not at all surprising. Covid is a respiratory infection. It kills the same way the flu kills (eg. pneumonia), so you'd naively expect them to have similar fatality rates and outcomes, and they do.


This entire thing has showed what happens when political leaders don't properly evaluate risk. It's difficult to do so when something new comes along. I think Wendover did a great job of address this:

https://www.youtube.com/watch?v=NtX-Ibi21tU


I can't really take anything seriously anymore:

> Aerosols can accumulate, remain infectious in indoor air for hours

I remember Michael Osterholm said CoV2 wasn't airborne, but respiratory, and he made the distinction airborne viruses stay in the air for hours (like Measles). "Aerosols" would indicate they mean respiratory but then they talk about it sticking around for hours.

> silent shedders

We are told there are asymptomatic people who spread the illness, but there is also tons of research to show they may not (https://pubmed.ncbi.nlm.nih.gov/32405162/) or that some of them weren't even asymptomatic; they had symptoms but no one asked (can't find that link).

This whole pieces seems like a long article to say "wear a mask," but all of us see people who wear a mask incorrectly or wear a cloth mask that isn't very effective against viral matter (https://www.acpjournals.org/doi/10.7326/M20-1342) and most people don't wash them daily, so they can build up moisture and bacteria (https://publichealth.uic.edu/news-stories/commentary-masks-f...). A lot of people treat them like a fashion accessory or just a thing they have to do and hang them up when they get home.

When states mandate masks, you're no longer asking people, and you brake the social contract. A lot of people do it just so they aren't shamed. A lot of people who don't wear masks do it as a political statement. When you boil it down ... it's all either political or shame.

There is a lot of explicit social conditioning and behavior modification going on here and it's sinister. I'm sick of pre-pubs that get contracted the following week and everyone going into hyper panic mode always. There are tons of secondary effects (people not going in for regular cancer screenings (https://unherd.com/thepost/professor-karol-sikora-fear-is-mo...), suicide attempts (https://archive.vn/N18t9), heart conditions, etc.) that will catch up with us.

I went into more detail earlier this month about getting fed up with our terrible information situation. This is not a time of honor:

https://battlepenguin.com/politics/this-is-not-a-time-of-hon...


I don't think the primary motivation for wearing masks is to protect yourself from others. It's to protect others from you. That's why there's shame involved in not wearing one; if you don't wear it, you're advertising that you don't care about the health of people around you. That's truly sinister.

Unfortunately, something as innocuous as mask wearing has been politicized in the US by certain unsavory political and media figures. In more enlightened countries and cultures (see most of Asia), wearing masks in the midst of a pandemic is just common sense. America is broken.


Unfortunately, I sympathize with the anti-mask requirement sentiment, even though I wear one in indoor public spaces like grocers. I don't think people should be shamed or that they should be mandated.

When I read into it it's not always clear masks work well to limit egress of virus, and I do think the scientific community is to blame to some extent for presenting things as "masks are scientific and lack of masks is not." This approach might only worsen things relative to a message of "we don't really know but it's a good idea to be prudent."

Linked scientific articles advocating masks I find are often misleading. They often are based on other viruses that potentially have other transmission properties, or make questionable assumptions, like that the mask is an n95 mask or is wet cloth. When I have found actual studies of SARS-CoV-2 with dry fabric of the sort most masks are made of, the masks work, but not nearly as well as you might think.

The problems with masks have really been underscored for me practically too. I've tried a couple of masks now, fit to my face, and I've run into a telling problem: when I breathe in mildly colder air, my breath shoots out from underneath my mask and fogs my glasses immensely. Not only is it evident in a very visible way that when I'm wearing the mask it's not actually blocking airflow very well, but then I have to constantly adjust things because I can't see, and sometimes have to resort to removing the mask entirely.

I still wear the mask and the fogging has gotten better as it's warmed, but my overall impression is that there are good reasons people might not wear masks, and I think the evidence in favor of them is much weaker and less rigorous than is often acknowledged. I think if the scientific community were being honest, they'd say they don't work great, but it's something, and every bit can count. That message seems to be enough; it would go a long way.


* I think if the scientific community were being honest, they'd say they don't work great, but it's something, and every bit can count.

Funny, because that's exactly my impression of what they are saying.


I am not sure the point of this rant. Anecdotally, it seems that countries where mask wearing is common are doing much better with respect to this virus.

Particularly, in Asian countries where mask wearing is already a somewhat common occurrence in public during the winter months.

Whether or not states should mandate masks is one question but businesses are entirely within their rights to require patrons to wear masks.

Whether people wearing masks for the right reasons or the wrong reasons doesn't seem that relevant to me. Shame is a motivating factor in many behaviors.

In short, wearing a mask is probably a good thing in the short term while we learn more about this virus.


Some people want to feel good about not wearing a mask, damn the consequences, damn the people hurt.

If 80% of Americans wore masks infections would plummet https://www.vanityfair.com/news/2020/05/masks-covid-19-infec...

If people are too selfish to wear a mask I have no problem with a mandate.


I think one challenge is that pre-print servers are meant for scientists, not the public. Take physics. If I read a paper on the arxiv in my niche, I can evaluate it's quality. I often referee papers. For me, it's useful to get the early result and if there are gaps, then it's on me to catch them. For those working on Covid19, they are experts, writing for experts. Someone may put out a paper about aerosols in enclosed spaces and how they linger. Someone else might write about how this doesn't verify if the virus RNA detected indicates a live virus. This is how science works and you are seeing it at an accelerated pace. It's actually rather beautiful. But, if you are say a journalist and don't understand this, you can see an article and write a story about it, without understanding that it is preliminary. In short (too late for that), the problem is not that articles on pre-print servers disagree ad we learn more (that's also science)--it is failure of reporting to inform people that these are preliminary results and could be wrong.


>Masks reduce airborne transmission.

Not as much as Ebola suits: https://www.welt.de/img/gesundheit/mobile130688133/039162761...

1 Ebola suit for everyone, with an air supply rucksack.


You try finding a PAPR in stock for sale to anyone who isn't a purchaser for a medical provider or first responder agency right now..

True story: I almost bought a 3M PAPR last fall because I wanted it for a "The Expanse" prop replica space suit I've been thinking about building. Decided that a few hundred bucks was too much to spend for the look of something alone, though. That would've been the best gratuitous purchase I ever made, in hindsight. Of course I probably still wouldn't be able to get filters for the thing, and properly caring for and disinfecting non-disposable hardware like that is nontrivial...




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