Why admitting Covid is Airborne is so hard

https://theair.substack.com/p/why-covid-is-airborne-history

by dsr12 • 5 years ago

115 77 5 years ago

theair.substack.com

j7ake• 5 years ago

Would COVID being airborne mean that one should wear an N95 mask rather than just surgical masks? Analogous to when doctors perform procedures on patients that may produce aerosols?

pasabagi• 5 years ago

Sure. That almost became the mandatory policy where I live.

MandieD• 5 years ago

It was the mandatory policy in Bavaria from about January to this week. At this point, I’m so used to the FFP2 mask I found that fits best that I’m still wearing those instead of the surgical masks we can (for) now wear instead - hooking behind the head is key.

himinlomax2• 5 years ago

Face shields as well. There was an Indian study showing that they reduced infections to nothing in social workers visiting unmasked people. Note that this also means that surgical masks should still prevent infecting others.

evilos• 5 years ago

Do you mean face shield only? That seems like it would be much worse than mask only, if covid is airborne as the article suggests. Mask plus face shield should be even better than mask only.

benf762• 5 years ago

Citation for the study? The Indians also used ivermectin to great effect to reduce their wave 2 months ago.

nikolay2• 5 years ago

There was a Swedish study showing face shields WITHOUT mask don't do anything. Also a study showing people with eyeglasses get infected less, i.e. it's possible that one can get infected thru eyes, although, I thing, it's pretty rare. Let's not forget that tear ducts drain in your nose!

spoonjim• 5 years ago

I’ve been wearing N95s since Day 1 and most clueful people who could get them were doing the same.

SideburnsOfDoom• 5 years ago

Nothing in this is binary, there are few 100% protections, there is only risk reduction.

Surgical masks reduce risk. N95 or FFP2 masks reduce risks more. So, prefer N95 masks. This does not mean that surgical masks or cloth masks are useless, or that N95 masks are perfect.

entropicgravity• 5 years ago

The empirical results of mandating masks is that virus spread is reduced substantially. But most masks people wear are not N95 type masks and shouldn't be as effective as the empirical results indicate. One article I read suggests that the effectiveness of masks comes not primarily from the filtering out of the virus but from increasing the humidity in the respiratory tract which in turn affects the ability of the virus to transmit disease.

nradov8• 5 years ago

A recent study found that in large populations, cloth masks were useless and surgical masks were only marginally effective.

https://www.poverty-action.org/publication/impact-community-...

But even with masks, over a long period the risk that everyone will eventually be exposed is close to 100%. That's why instead of obsessing over masks we should focus on vaccinating as many vulnerable people as possible.

https://www.businessinsider.com/delta-variant-made-herd-immu...

benf762• 5 years ago

It means that cloth fabric does nothing against aerosol. Even N95 masks don’t filter out all virons which can be as small as 1nm and escape the electrostatic charge of the N95. Security theater.

beeforpork• 5 years ago

No, this is misinterpretation and too absolute a conclusion. The truth is not found in extremes. Protection is about reducing viral load -- it is useful even without fully eliminating viral load. A cloth facemask does get damp when you breathe through it, ergo some of your exhaled water (= infection carrier) got caught. An N95 mask catches a lot more. You need a bit of viral load to get infected, so whatever reduces viral load will help.

It is dangerous to immediately conclude that aerosol transmission makes masks security theater. They do not, they do help a lot.

thehappypm2• 5 years ago

I had a hair on my phone, and I tried to blow it off while wearing an N95. Nothing. Even air itself is substantially slowed through an N95. It's the difference between sucking a viral load at full speed into your lungs, and having it crawl through a barrier at extremely low speed.

murgindrag• 5 years ago

My impression is that there are rapidly rising and then diminishing returns on investment.

Going from cloth to any mask with a high filtration layer is a huge improvement. Cloth is <30% of small particles. High filtration layer is >90%. Beyond that, the benefits are questionable.

Some surgical masks include a non-woven layer, and those already do pretty well (but how would you find those? pre-COVID it was easy). From there, genuine (non-counterfeit) KN95 and nanofiber masks are a big step up, and incredibly effective. At least pre-delta, if everyone used those, combined with modest social distancing, there was very little spread.

N95 masks are a modest improvement from there in terms of filtration, but by that point, mask quality (at least pre-delta) no longer appeared to be the dominant risk factor. COVID19 can spread through other mucous membranes (e.g. eyes). While combined with a face shield, used correctly, etc. I'm sure N95 make a difference over KN95, in practical public health use, I doubt there's any difference.

This is a good summary of data:

https://docs.google.com/spreadsheets/d/1M0mdNLpTWEGcluK6hh5L...

https://docs.google.com/spreadsheets/d/1i06OAItoOwIUaMjElr8m...

I don't really distinguish between things with >90% filtration. Unless you've got an excellent seal and are otherwise protected, it doesn't matter much. Note that the measurements are performed at 300nm. There isn't much spread at 300nm (a single virus particle is unlikely to make you sick). A 90% mask at 300nm will have >>>90% at e.g. a micron. A micron particle is unlikely to have more than one or two COVID particles (a micron is 5 COVIDs wide).

I do distinguish based on pressure drop. Lower means more air goes through the mask, rather than around.

I also do distinguish based on technology. The nanofiber ones don't degrade the same way as N95. The N95 nonblown layer will theoretically beat nanofiber for the first couple of hours of use, but once it's moist from your breath, nanofiber beats it. Personally, I use a disposable nanofiber mask, and I consider it a better (e.g. safer) option. I'm not in a controlled cleanroom/hospital setting, and life happens. Masks do get reused, abused, rained on, and generally exposed to life. Nanofiber have much better durability.

I also supply chain. Amazon and eBay are rife with counterfeits. I like masks where I can order direct. Especially 3M tends to be mostly fakes, unless ordered through authorized distributors.

I distinguish on fit. In addition, a well-fitting 90% masks beats a poor-fitting 99% mask, since with a good fit, all the air goes through the mask. Order yourself a variety pack and see what's comfortable and fits.

The biggest thing you can do is limit yourself to settings where everyone uses reasonable precautions. All parties wearing KN95 masks, having reasonable social distancing, favoring outdoors, vaccinated if >12, etc. is pretty safe. If you have a mixture of extreme precautions and no precautions, everyone is at risk.

GeekyBear• 5 years ago

Would COVID being airborne mean that one should wear an N95 mask rather than just surgical masks?

Yes.

Studies that have been done show that if an individual might get infected within 15 minutes in a room, by time and concentration of the virus in the room, add a face cloth covering you only get about five more minutes of protection.

On the other hand if you use the n95 respirators and fit them tight to your face, you can actually spend 25 hours in that same room and still be protected.

https://www.pbs.org/wnet/amanpour-and-company/video/do-masks...

ncmncm10• 5 years ago

We have to realize that medical doctors are not, as a rule, scientists. They typically get their doctoral degrees without personally ever doing any actual science, beyond pre-cooked experiments in lab classes. Instead, they have read a great deal about what other people who did science said. But what people say is not the same as what they do, and paying attention to what they say is not a substitute for doing what they did.

Instead, doctors are obliged to memorize a great deal of what they are told are facts. Probably most of what they are told really are facts. But there is nothing systematic distinguishing facts with a great deal of support from those that are just repeated lore, like the business about airborne disease transmission.

Doctors have rejected evidence for airborne transmission because it contradicts what they were taught are facts, with no warning about how shaky any asserted fact is.

Another source of resistance is that facts, to be believed, need a theory. A fact without a theoretical mechanism by which it must operate is rejected. We saw that for cholera before germ theory made sense of it.

For a current example, in doi:10.1093/gerona/glab115, it turns out that having had a recent TDAP vaccine (which you can ask for at any pharmacy) turns out to predict, very robustly, a 40% decrease in onset of dementia among patients at an age where they are at risk for it. A 40% effect size is enormous! At this point, nobody knows why. Is it the tetanus, the diphtheria, the pertussis antigens? Or something else mixed in? Nobody knows. But without a demonstrated mechanism, nobody can allow anyone to see them to take it seriously.

scoutt2• 5 years ago

Yes. It's called Applied science (https://en.wikipedia.org/wiki/Applied_science).

"Applied science is the use of the scientific method and knowledge obtained via conclusions from the method to attain practical goals. It includes a broad range of disciplines such as engineering and medicine."

It's different from experimental/research science. Nothing new.

truth, to be believed, needs a theory

Science is not the pursuit of "truth".

"If it's truth you're looking for, Dr. Tyree's philosophy class is right down the hall." - Prof. Indiana Jones

ncmncm10• 5 years ago

You are confused in exactly the same way as everyone at the CDC who insisted, and continues insisting, that airborne transmission of COVID-19 does not happen.

ElFitz3• 5 years ago

Science is not the pursuit of "truth". "If it's truth you're looking for, Dr. Tyree's philosophy class is right down the hall." - Prof. Indiana Jones

Quite funny because Indiana Jones is an archaeologist.

And supposedly teaches history, which often is a form of social science.

One of these few sciences where it is commonly admitted that most evidence is tainted by biased as well as both personal and limited groups' interests.

Even taking aside the fact that it’s a fictional character invented by some people more interested in telling fun stories than anything else, using this as a call to authority to support a view on any science is quite hilarious.

Your view on science also reminds me of how, in med school, a professor once told us "medicine is not a science; it’s an art".

Which, to me, has since been a good way to know which health professionals to stay clear of.

flemhans• 5 years ago

Is it true that nobody knows how acetaminophen works?

krageon• 5 years ago

Although its exact mechanism of action remains unclear [...]

Quote is from https://www.ncbi.nlm.nih.gov/books/NBK482369/ , which has last been updated this year (or so it says). The studies quoted are from 2016 and 2009, so any real insight would have to be very recent.

ncmncm10• 5 years ago

Badly. Acetominophen works badly.

As I understand it, it makes you oblivious to suffering, incidentally including your own.

hajile• 5 years ago

It's also true that a lot of trials show that it's only a couple percent more effective than a placebo.

That fact is even more true about anti-depressants. Tons get rejected because they are only 1-2% more effective than a placebo. Even worse, we make the anti-depressants and don't actually have any real idea about what causes depression in the first place nor what exactly the drugs are treating.

We're also really bad about long-term side effects.

Meridia was pulled after something like 15 years.

Permax after 20 years years due to causing birth defects and other things.

Cylert was an ADHD drug pulled after 30 years.

Accutane (for acne treatment) was pulled after around 30.

Pentylenetetrazol was pulled after 48 years because a whopping 42% of the people who took it got spinal fractures from the seizures it caused (not to mention all the other body damage to other bones and muscles).

Propoxyphene (pain killer) was supposed to be pulled in the 70s, but the FDA waited 55 YEARS until around a decade ago to pull it.

And if you look up lists of recalled drugs and their reason for recalls, there's hundreds with many having been in use multiple decades and sometimes like these, despite the high risk being well known.

That's just one problem with the FDA and big pharma having a revolving door policy.

nradov8• 5 years ago

Medical doctors and scientists are happy to use pharmaceuticals for which the mechanism of action is unclear as long as experiments show a dose response curve. If we can see that the response increases with higher doses then we can be confident that there's a causal relationship rather than just a spurious correlation.

For example SSRIs are widely used and empirically seem to be effective for some patients with chronic depression, but there's still no firm consensus on why they work.

ncmncm10• 5 years ago

SSRIs, and anti-depressants in general, are subject to an unavoidable failure mode of evidence-based medicine's "gold standard", randomly-controlled trials (RCT): ambiguous diagnosis.

If you are unable to distinguish between a half-dozen causes for what appears to be the same illness, your RCT of even a perfect cure (for one of the causes) will show arbitrarily small positive effects, and possibly large negative effects, according to the prevalence of each actual cause represented in the sample population.

Thus, we see assertions in scurrilous publications that "anti-depressants don't work any better than placebo", despite that they make the difference for millions of real patients between 100% dysfunction and normal life. Psychiatrists are stuck with no better means to diagnose the different kinds of depression than to prescribe different anti-depressants, one after another, and see which, if any, help.

It is almost miraculous that the anti-depressants we have were approved. It is doubtful they would be approved today. That is a consequence of fetishizing RCTs as "the gold standard" to imply that no further thought is needed in evaluating its results.

The world economy has abandoned the actual gold standard, for reasons.

... But, yes, to your point, there are certain ad-hoc routes by which evidence can sometimes get through to medical practice despite typical epistemological roadblocks.

atoav• 5 years ago

Medical doctors and scientists are happy to use pharmaceuticals for which the mechanism of action is unclear as long as experiments show a dose response curve.

All medical doctors? Or many? Maybe just some? (Doctors over here in Europe certainly wouldn't do this commonly without recommendation of national institutes, as demonstrated by the Cov19 vaccines). I think the underlying question is strongly linked to the actual numbers. You could have 90% of doctors agree with the airborne idea (or admit they don't have the expertise) and with 10% rejecting the idea patients would still be in doubt or pick the thing they like more ("Energy crystals!").

didntknowya• 5 years ago

sure, doctors are not scientists. they're not out there inventing or researching new things, but they still need to use logic to work things out, based on the scientific knowledge available.

of course bad things happen when they presume that the facts they read are 100% true, and we now know a lot of them are drip-fed false facts by big pharma, sales rep etc. with hidden agendas. also there is a tendency for experienced docs to get caught up in their own ego and start acting with their own bias, which happens in all professions.

gumby• 5 years ago

The article mentions masks only once. What is the point of a mask but to suppress airborn transmission?

detaro• 5 years ago

Prevent droplet spread.

galaxyLogic• 5 years ago

I don't think anybody expects a mask will fully protect them. But they help. And they provide an important psychological benefit: They make people aware that the virus is still amongst us. They put social pressure on other people to conform and wear a mask like everybody.

taurusnoises• 5 years ago

I also think that part of the resistance to calling Covid transmission "airborne" has to do with containing mass hysteria. Droplets are "things," matter we can wipe away, dodge like bullets in The Matrix. A virus being airborne instills an even greater level of fear then is already apparent, because "airborne" takes the control out of it. "How can we clean the air?" Air isn't a "thing." Even the arguments for the airborne theory (which I'm partial to believe) are basically trying to make manageable a concept that seems impossible to manage--the cleaning of the air, the idea that airborne does not necessarily mean "out of our control."

gruez• 5 years ago

A virus being airborne instills an even greater level of fear then is already apparent, because "airborne" takes the control out of it. "How can we clean the air?" Air isn't a "thing."

What about air filters? IIRC at the start of the pandemic various transit authorities and airlines were assuring the public that travel was safe-ish because their vehicles ran HEPA filters.

MichaelZuo• 5 years ago

If the airflow rate is sufficiently high than that would be true.

sonicggg3• 5 years ago

The answer is simple, you don't need an entire article on that. It's all politically motivated. Accepting it as airborne would force governments to accept the costs of fighting it.

Forget that "keep the 2m distance" nonsense. Airborne means you need N95 required everywhere. Public gatherings are out of question too.

And if you fight the narrative, you can easily be labeled as "anti-science", whatever that means. Did you all forget how the mask guidance was changed overnight around April/2020? All in the name of "new science information".

Take any information from the CDC or WHO with a large grain of salt.

nradov8• 5 years ago

Regardless of whether the virus is airborne or not, there is no need to require N95 masks everywhere or prohibit public gatherings. All exposure control interventions are ultimately futile. They can perhaps slow the spread down slightly to reduce impact on the healthcare system but we'll all eventually be exposed no matter what we do. Fortunately the vaccines are very effective at preventing deaths.

https://www.businessinsider.com/delta-variant-made-herd-immu...

sharx• 5 years ago

"slow the spread down slightly to reduce impact on the healthcare system" is pretty important during these big waves. Banning outdoor gatherings is probably overkill though, I believe the worst places still have maskless indoor activities.

sonicggg3• 5 years ago

Why are people so obsessed with death count? We still don't understand the long term effects of this virus. You don't know the "Long Covid" count for example. And there is very little evidence that vaccines are effective at preventing that.

2OEH8eoCRo0• 5 years ago

The answer is simple

Kiss of death right here. If you think any of this is simple then I have a bridge to sell you.

And why is there always the need to invoke conspiracy here lately? Don't trust the CDC or the WHO? Yikes!

sonicggg3• 5 years ago

https://mobile.twitter.com/WHO/status/1217043229427761152

Please, go on

dirtyid• 5 years ago

A friend working in gov lab responsible for measuring covid airborne behavior said there's a lot of expenses, liabilities involved in formally labelling covid as airborne. The amount of resource intensive measures needed to make spaces not occupational hazards because covid is legally recognized as airborn is onerous.

curryst• 5 years ago

I don't think it's necessarily political.

One of the issues is that airborne diseases have a totally different set of requirements for hospitals, and they're much harder and more expensive to comply with. Specifically, patients with contagious airborne diseases need to be kept in rooms with lower pressure than the rest of the hospital to prevent contagions leaking out. I would imagine we have even fewer of those than we have ventilators and ER beds.

Of course, we can free doctors of that restriction, but I don't know how much we stand to gain versus any losses that occur in the transition period as hospitals wonder what the guidelines are.

The other complication is that as I understand it (and I could be wrong), airborne vs droplet is not a hard and firm line, it's more of a spectrum. The distinction seems to be largely in how long a space will "carry" the disease. Things like the flu aren't typically considered airborne because they don't hang in the air for very long. If someone coughs on you, you might get infected. If you walk through a grocery store an hour after someone with the flu walked through, you're probably not going to get infected.

Measles is a classic airborne illness because the space is infections for ~2 hours after someone with measles walks through.

Some think the distinction is outdated, and anything that spreads via the air should be considered airborne. Others seem to think that larger particles should be considered airborne.

At any rate, I can see some validity to attempting to maintain the status quo. Several regions are in the midst of severe COVID outbreaks, and given the upheaval an airborne recognition would create, I think the CDCs stance of strongly hinting that it's airborne without declaring it such is reasonable. They don't seem to be denying it's airborne, just not officially declaring it so.

We can loop back and formalize the airborne status later, when hospitals aren't swamped. I don't want to stress already stressed hospitals, and I don't want to overly stress our healthcare workers. They have it hard enough, and we are having a hard time getting enough of them.

LorenPechtel3• 5 years ago

I do agree that airborne vs aerosol is a spectrum, but I do think not admitting it political. Admitting it would mean N95s should be used more widely.

As it stands we have "face covering" mandates in some places when it should be surgical or higher and should actually be enforced.

joe_guy• 5 years ago

I am curious, in a non-mask effectiveness doubted sort of way, if it's known that surgical masks perform better than a well-fit cloth mask, at protecting the wearer?

thinkingemote• 5 years ago

Covid-19 is the disease which one can get from the virus.

The actual virus which is spread around is SARS-CoV-2.

I would only hope that those speaking about this would understand it by now.

achenatx3• 5 years ago

even scientists often times use the disease name interchangeably with the virus.

achenatx3• 5 years ago

Airborne has special meaning. Clearly covid spreads "through the air" that doesnt mean it is airborne.

One problem is there is no strict definition of airborne. There is no doubt that covid can spread via an airborne path, but it may not be the dominant path.

The original variant had about a .7% infection rate through casual contact. For people living in the same household it was something like 12%.

When people talk about airborne, one implication is that it floats in the air and is infectious for a long time. This generally means a much higher rate of transmission. One factor in this is the infectious dose. The lower the infectious dose, the more likely it is to be airborne. A TB infection can start from one bacterium. So even though they are huge, it is airborne.

Delta is 2X more infectious than the original, that means it likely needs a smaller infectious dose and is more likely to transmit via airborne particles.

Just because covid can transmit via an airborne path doesnt mean it is the main way it is transmitted. When we think of airborne we think of highly infectious viruses like the measles virus.

Measles is so contagious that if one person has it, up to 90% of the people close to that person who are not immune will also become infected.

Measles virus can live for up to two hours in an airspace after an infected person leaves an area. >>

Arete314159• 5 years ago

The evidence that sars 1.0 was airborne was already in medical journals. I am not a scientist or a doctor, but I found it on pubmed in feb of 2020.

While the history of science aspect to the denial is important, we cannot discount good old fashioned greed. If Airborne Covid is the messaging, then people don't want to shop, fly, or do lots of things where they spend their money. If however we have messaging about 6 feet apart, wash your hands, etc., then folks will still spend money.

nikolay2• 5 years ago

I am surprised nearly all measures around the globe ignore the fact that the main method of infection is the aerosol one. People still damage their lungs inhaling alcohol vapors and other toxic disinfectants, still waste resources wiping stuff up, and washing frantically their hands, wear masks that do little, instead of focusing PPE on protecting the eyes and wearing aerosol-filtering masks like KN95, N95, KF94, FFP2, and higher grades!

Why admitting Covid is Airborne is so hard

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