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Did the Great Aerosol Debacle Really Matter?

A few days ago the CDC changed its official guidance about COVID-19, finally acknowledging that one of the primary transmission routes for the virus is via airborne aerosols. This prompted a lot of criticism about the CDC being extraordinarily late to admit this.

There's a lot I could say about this, but I won't for now. I just want to ask one question: Why does anyone care? The CDC's official guidance may have been slow to change, but as early as last May they were publishing research that acknowledged the possibility of airborne transmission. In August they formed a task force to investigate transmission modes. By September Dr. Fauci was publicly conceding that COVID transmission was "much more aerosol than we thought." In October the CDC's official guidance acknowledged the existence of airborne transmission. Super-spreader events (which are indicative of airborne transmission) had already been in the regulatory eye for months. And very early on the CDC was recommending better ventilation to rein in virus transmission, which mostly matters only if the virus is airborne.

Illustration from a May CDC publication acknowledging the possibility of "super-emitter" aerosol transmission at a choir practice in Skagit County, Washington.

So we were already focused on super-spreader events and the CDC was recommending better ventilation. What would have been different if the CDC had acknowledged the aerosol infection route earlier? A little less obsessive surface cleaning? (Though the CDC always said that surface transmission was rare.) Social distancing at ten feet instead of six?

I'm not sure, but this is a genuine question. I know that hospitals fought against acknowledging airborne transmission because it would have required them to adopt protective gear that was both more expensive and more cumbersome. An official change in CDC guidance would have had a big impact on them. Beyond that, though, I'm a little hard put to figure out what would have changed outside the hospital world if the CDC had been quicker on the ball. As Fauci said in October,"Rather than getting bent out of shape of, what's the evidence of 5%, 10%, 20%—aerosol transmission almost certainly occurs, then act like it's occurring. And then do the same thing you've been doing otherwise."

So: was the public response to COVID-19 really hindered much by the CDC's sluggish official guidance? Can anyone help me out here?

82 thoughts on “Did the Great Aerosol Debacle Really Matter?

  1. Jasper_in_Boston

    They and Fauci are the face of the pandemic, and as such are convenient whipping boys. I really do think this is a big part of it. I've been going over the evidence for the "Fauci lied about masks" claim, for instance, and I see little or nothing to back up that allegation.

    People are stressed, probably even traumatized, and the public health establishment is a convenient target.

    1. Dana Decker

      Fauci lied when he recommended surface cleaning but *at the same time+ discouraged mask wearing.

      There is no excuse for that. If the means of transmission are unclear - as they were in late March to at least mid-April - what is the logic behind not recommending all possible mitigation efforts?

      Given the success of masking (mostly in Asia) to reduce flu, there was a good chance that it would also be effective against COVID. Failure to put masking at the top of the list was driven by other consideration, which the public were not privy to.

      1. Bardi

        "There is no excuse for that."
        I seem to remember that, at the time, there was a shortage of PPE, which included masks. I remember, at the time, to try to acquire masks as soon as available. The shortage could have been alleviated had mr. trump activated emergency manufacturing capabilities, something well within his capabilities.
        Not excusing what was said, but, there was at least one "excuse" for that, fear of forcing a "run" on such equipment would certainly deprive essential workers of things they, and the community, needed.

      2. Jerry O'Brien

        Mask-wearing, I figure, wasn't at the top of the list for the general public early on because it WAS at the top of the list for nurses, doctors, and medical technicians dealing with patients.

      3. weirdnoise

        Masking and other PPE for those directly exposed -- healthcare workers -- WAS at the top of the list. Fauci was clear on that. There was equivocal evidence on whether it was helpful to the general public, and he did play that up at first. And, in fact, until the focus fell on masking's effect on the infector and not the infectee the evidence wasn't very strong that unfitted cloth masks did much good.

        1. Joel

          The evidence is still not strong that unfitted cloth masks do any good unless the wearer is coughing and/or sneezing. They mostly served to prevent people from touching their noses and mouths and as a reminder to social distance.

        1. Jasper_in_Boston

          Nickel version is: Fauci definitely said in early March "It's not a good idea to walk around in a mask."

          This was during a 60 Minutes interview on 3/6/20. Obviously that's bad advice, so, if you want to criticize him for getting something wrong, have at it.

          Fauci claims the medical community did not yet realize that many covid cases were asymptomatic, and that such cases accounted for a substantial portion of the transmission. (The implication being they thought "healthy" people had no reason to wear masks in public, especially in light of the supply issues affecting healthcare workers).

          By the beginning of April the evidence on asymptomatic spread had begun to gather, and so Fauci's messaging on this also changed. And by the way, WHO didn't change their official advice on masking until early June. Were they, too, "lying?"

      4. Salamander

        "Fauci lied when he recommended ...."

        Bull. This was at the very beginnings of the pandemic, when they were still calling it the NOVEL coronavirus, because it seemed to behave so differently from other viruses. A "lie" is when you deliberately state something that you know isn't true. Dr Fauci gave the best recommendation he knew - AT THE TIME.

        Now, Trump lied. Over and over again. He knew that everything he was saying was false. He's still lying. His case is different.

        Also, in condemning the CDC, note that good solid research takes time, to check and recheck to confirm, and to get more detail. Look how long it took to verify that the vaccines that were in the pipeline by February actually were "safe" and "effective."

        Life ain't a 30-minute teevie show. McGyver was a fictional person.

  2. Pittsburgh Mike

    I'd imagine that schools and offices that reopened could have put more effort into improving air flow and ventilation if they knew that aerosol transmission was the primary Covid transmission mechanism.

    I do wonder who didn't know this, though. If you read description of super-spreader events even moderately obsessively, you'd know that you could have terrible events as long as they were indoors and badly ventilated, and it didn't matter if people stayed apart and covered every surface with alcohol.

    So, unless you believed in magic, it was obvious for months that this spread by aerosols.

    1. AlHaqiqa

      Unfortunately, many people didn't realize this and were condemning and judging others for enjoying the great outdoors and officials closed the beaches and parks. In Massachusetts, we lagged far behind the literature as we followed federal guidelines to a T.

      It seems like the public health officials were afraid of loosening regs despite the science, until the dam broke this week.

  3. julierwright

    As a teacher, I've followed what's been happening with schools not just in my area but nationally, and I believe the lack of guidance around ventilation has had a big effect on policies and politics around what goes on in school buildings. Many classrooms have no openable windows (or are in places where it's too cold to open windows in some months). Many school buildings, like those in Portland, OR where I am, have horrific ventilation because the systems are so outdated and poorly maintained. So if CDC guidelines and the state policies derived from them had acknowledged the importance of ventilation, those rules would have precluded opening some classrooms.

    In Portland, union pressure resulted in ventilation devices in every classroom or office where students are. We also open windows in classrooms that have them, and the earlier 6-foot guidance is still in effect thanks to the agreement between the union and the district. I believe those steps reduce the odds of transmission and keeps my students and their families safe, although the rise in cases in Oregon that happened soon after the reopening of many school buildings certainly gives me pause.

    Hybrid teaching is still horrific, but that's another story. I am so very frustrated by the public and media perception that teachers want to be out of school buildings. That's been true in the sense that many of us have believed that it was necessary to prevent serious illness and death, but as far as the logistics of teaching and learning go, this year has been a nightmare and so many I know are quitting. From a job and education point of view, this is not what any of us would have chosen! We are longing to get kids and their families vaccinated and use school buildings fully again, and drop the hybrid monstrosity.

    1. MontyTheClipArtMongoose

      But, in Portland, you also are vaccine hesitant to the maxxx.

      Though I give PDX credit: this was my first winter here without nigh nightly news reports of multiple measles cases. Only took three years, & a plandemic, to clue the Homeopath Moms & Militia Dads into the utility of inoculation.

      1. julierwright

        I agree with you that vaccine hesitancy about childhood vaccines is a maddening thing about Portland. It is (no shit) one reason I became a math teacher in my 40s: I knew many otherwise thoughtful, intelligent parents who were spouting nonsense pseudo-math to justify not vaccinating. But I don't hear a whisper of anti-covid-vaccine sentiment in the same circles so far.

    2. golack

      Thanks.
      That does seem to be the case--schools could reopen safely, if done right. The problem has always been getting it done right. And most public schools did not have the resources to do it right--so limited numbers.
      It's not just the classroom either. It the bus, congregations before/after school, etc.

      1. Crissa

        There's something different about a bus from those others.

        It's that people aren't going there to talk. Spread is not connected to mass transit use.

        1. lawnorder

          Unless things have changed enormously since my kids were in school, which wasn't THAT long ago, the passengers on school buses definitely do talk. You're right about public transit; there's very little talk.

  4. rick_jones

    The CDC and similar organizations are held up as "the authority" from whom we are supposed to receive, accept, and follow guidance. When they are not timely or they prevaricate, and when things evolve it diminishes the argument they should be heeded "because science." Whether that puts them in a Kobyashi Maru situation or not.

  5. Brian Dell

    It fundamentally changes the mask debate. It means that cloth masks and even surgical masks are a poor substitute for a fit-tested N95.

    Can you fit test the whole population and supply them with N95? No, but 1) had everyone darkening the door of a nursing home received this it would have cut the death rate down significantly 2) if we aren't going to pull infected people out of homes and put them in centralized quarantine to stop household transmission, we should be bringing in the household for fit testing and supply of N95s. Essential workplaces could have also been targeted. This would have cut into the considerable transmission that was occurring that the other measures like closing schools weren't mitigating.

      1. Special Newb

        You can wear safety glasses if you are tending a patient stuck in a room. Ventilate the room and hall outside it and you have a good barrier

    1. Crissa

      No, it doesn't.

      If anything, it shows that masks are even more effective.

      Because the aerosols are the size that get absorbed by the cloth.

    2. Salamander

      Thanks for mentioning "fit testing". I've fit tested a lot of people, and a pretty good number of them in N95s this year. Besides getting the right size and model (which was all but impossible for awhile), the wearer needs some basic training on how to put the thing on -- also, to take it off, without re-contaminating themselves.

      Most people intuitively do it wrong.

  6. ey81

    Resources are finite, and if you distract people into doing a lot of surface cleaning when they should be focused on improving ventilation, you deploy finite resources inefficiently, and people die. Also, for legal reasons, many organizations consider it safest to rely on official pronouncements. So if the CDC de-emphasizes aerosol transmission and focuses on disinfecting surfaces, many organizations don't feel free to read the literature themselves and make their own decisions: they go with the official recommendation.

    1. Gene Ha

      🠕🠕🠕 Kevin, this!!! US states' pandemic rules still don't take aerosol transmission into account.

      Even when states do have rules, the rules are still based on influenza. Wipe down surfaces like doorknobs. As long as you avoid droplets flu is almost never transmitted by aerosols (which is the real reason why Fauci didn't recommend masks for months). The whole "restaurants can open at 50% capacity" rules have been a complete failure.

      1. Jasper_in_Boston

        which is the real reason why Fauci didn't recommend masks for months

        Months?

        This is pretty misleading. The pandemic began to hit the US with full force in March, 2020. Fauci recommended mask-wearing in early April, 2020.

        Also, the available evidence suggests de-emphasizing mask-wearing was grounded in a misunderstanding of the prevalence and infectiousness of asymptomatic covid cases -- it had nothing to do with uncertainty about arenol transmission.

      1. Special Newb

        By refusing to follow the overwhelming evidence of aerosol transmission and update their guidance they allowed states to have the legal cover to ignore it. Which they mostly did because it's hard.

  7. Dana Decker

    At the end of March - when the means of transmission were not completely understood - the CDC

    recommended wiping surfaces
    DISCOURAGED mask-wearing

    That was unethical. You don't know what will be effective, but don't recommend all possible mitigation efforts? No wonder the CDC is viewed as an unreliable source of advice.

    1. Crissa

      Weirdly, you don't provide context to your statement, which is probably because it would show why they did those things.

      And wiping surfaces is still recommended. It solves other diseases, you know.

      1. ey81

        A lot of things are "recommended." Nobody could do all of them. It would make a lot more sense, if your purpose is to maximize human welfare, to add a math teacher at your local high school so that the sections could be smaller, than to hire two extra custodians to disinfect every surface regularly.

        1. Crissa

          Weirdly, I don't know of any school hiring two extra custodians instead of teachers, assuming the teachers are even available.

    2. Jasper_in_Boston

      It's certainly not "unethical" to make recommendations you in good faith think will save lives on net. I do give you credit, though, for acknowledging "the means of transmission were not completely understood."

      The United States CDC is far from blameless in their handling of the pandemic -- let's be clear on that. Their role in the covid test debacle is highly damning. That was a true disaster, and in my view easily dwarfs any of the other mistakes they made. The country was left flat-footed in terms of tracking the outbreak at a critical time.

  8. painedumonde

    I made it through without infection and only droplet protection... The answer might be less than what's stated but more than was.

  9. Seán O'Halloran

    I would suggest earlier recognition of aerosol Covid would have led to the CDC reccomending tight-fitting N95 masks for use by citizens, to be worn under cotton, or whatever second layer mask people wanted. The acceptance of the aerosol as primary means of spread hypothesis would also have seen a lot less money wasted on perspex shields, which reduce the free flow of air and create eddies where Covid aerosols can linger, increasing the chance of infection.

    1. weirdnoise

      Of course. And with Jared in charge we would be hip-deep in N95 masks by the summer of 2020.

      It's been well over a year and there still are shortages for healthcare workers in some places.

        1. MontyTheClipArtMongoose

          Your party, given its fealty to Ivanka Trump's Secret Lover* & the Redneck Riviera Peter Pan**, always strikes me as more a Secind Mile kind of deal.

          *El Jefe Maximo de Maralago.

          **Cocaine Cowboy Pansexual Matt Gaetz.

    2. Crissa

      You can't infect yourself with your own aerosols. You can't going to have eddies of someone else's breath under the shields.

        1. Crissa

          Well, I've not seen any classrooms where they exclusively used short shields.

          And that example has a weirdly tall person breathing over the top.

          So... Why would I think of something I've not seen anywhere, and your example is rendering?

  10. Special Newb

    It matters a ton for say schools. Schools everywhere leaped to pure hygeine theater. With a direct CDC statement the government has to face facts on ventilation, you don't get days lost to deep cleaning. Many schools still have bad ventilation. Or since aersols are the main vector, a clear early policy statement instead of hedging might avoid stupid stuff like closing parks etc. So yeah it matters.

  11. Gene Ha

    Why is no one commenting about indoor dining? The whole "25% capacity" or "50% capacity" restaurant and bar rules supposedly control droplet spread, but make no sense now that we know the virus is spread by airborne aerosols that can fill an unventilated room. See this El Pais animation from last year: https://english.elpais.com/society/2020-10-28/a-room-a-bar-and-a-class-how-the-coronavirus-is-spread-through-the-air.html

    US states (like my Blue state of Illinois) still act as if COVID-19 is only spread by droplets that fall to the ground 6 ft from the infected. That's the logic behind "50% restaurant capacity." But if people hang out for 2 hours in a closed room eating and drinking without a mask, the aerosols will build up in the room and infect multiple people. The El Pais has common sense advice on how to handle aerosol spread, which STILL are NOT informing US pandemic rules.

    1. golack

      Thanks for the link. The models compare no to good ventilation, and gives a good idea of what is needed to help.
      The reduced capacity rules assume some ventilation and that the odds of having an infected individual in there at any given time is limited, therefore limiting the number of people who could be infected.
      You're right that they started reopening too early--if the waited a week or two longer earlier this year, we'd be in much better shape now. I've seen news reports of some places installing air filters to minimize viral load inside, but then still not being allowed to open up. I haven't seen any programs that let places that invest in ventilation open up sooner--which would be good.

    2. Jasper_in_Boston

      Indoor restaurant dining should have been closed down early, and nationally, and not be allowed to resume until vaccine supplies were ample.

    3. Special Newb

      I disagree that capacity rules are a total bust. If these places have some ventilation but not great ventilation due to design choices the lower amount of coronavirus aerosols put out by 25% occupancy vs 75% will make it easier for ventilation to thin out the virus.

  12. azumbrunn

    There are know-it-alls who love to criticize for example the CDC for something they allegedly got wrong, just to prove how smart they are. Though in fact they are just being Monday morning quarterbacks.

  13. Mitchell Young

    Covering for 'the experts'. Typical.

    I was for masks before it was cool. I have been anti-mask for quite some time now. In most places...certainly outdoors, driving in your car alone, they are unnecessary.

    The CDC was wrong. Pelosi (end Feb 2020) was wrong when she encouraged people to come to Chinatown (the original one, not Irvine). De Blasio was wrong when he encouraged people to get out (mid-March 2020).

  14. Mitchell Young

    Top three Covid deaths per capita still all blue.
    NJ
    NY
    MA

    (MA hasn't gotten enough criticism. They are supposed to be super smart).

    1. KenSchulz

      Yeah, couldn’t have anything to do with Boston and especially New York getting huge numbers of international travelers early on when little was known about Covid -19 ...

      1. MontyTheClipArtMongoose

        Yup.

        & Massachusetts has a Trump, but respectable, businessman GQP governor.

        So, it's hardly a bluetopia.

  15. D_Ohrk_E1

    "I know that hospitals fought against acknowledging airborne transmission because it would have required them to adopt protective gear that was both more expensive and more cumbersome."

    That's not really it. Hospitals rushed to make huge changes to their HVAC systems to provide negative air pressure in COVID-patient rooms. That was an inherent acknowledgement that the virus was aerosolized. Maybe some smaller, rural hospitals fought against that, but I doubt it; they were all trying to stop the spread within their own walls.

  16. D_Ohrk_E1

    BTW, I want to remind everyone that I specifically said very early on, that 6 feet was inadequate as the 6 foot distance was based on old science, that new science had shown aerosolized particles extending as much as 16-18 feet or more.

    And, I told you from the start that the mask guidance at the start was wrong, that it was aerosolized and you needed to wear a mask.

    And even before this, I told you that there was definitely something very bad going on in Wuhan.

  17. Salamander

    Swiss cheese. Surely you've seen the diagrams? By using several layers of ineffective protection, the end result is pretty good protection?

    So you have your cotton face mask. Then you have your six foot (or two meter) distancing. You've got your frequent hand washing, and exhortations to not touch your face. The avoiding indoor spaces, or greatly limiting capacity, so as to maintain the distancing and give the HEPA filters a chance.

    Each one is an inadequate protection. Put 'em all together, and we can stop the pandemic. Or we can quibble about trivia and look to blame the good faith efforts of medical experts.

  18. theAlteEisbear

    My dad had a good answer to your retroactive question re the CDC, Kevin: if the dog hadn't stopped to poop, it would have caught the rabbit.

  19. KenSchulz

    I hope the meta-lesson we learn from this is the one the countries of the Asia/Pacific region seem to have learned from SARS-Cov-1 — faced with a novel contagious, sometimes fatal disease, assume the worst. Assume that it can be transmitted by any mechanism associated with the systems it infects, assume it can be transmitted during latent and/or asymptomatic periods. Before a test is available, assume that everyone with potential exposure is infected; once a test is available, test widely and frequently. Be prepared with a well-staffed and well-trained public-health service; contact-trace zealously; stockpile massive quantities of PPE.
    Don’t try to fix blame, fix the system!

    1. Vog46

      ^^^^^^^^^THIS^^^^^^^^^^

      Ken-
      You nailed it. It does however go against everything that efficiency experts - proponents of Just-in-time delivery have espoused for decades. Of course THEY never planned on a pandemic causing the supply chains to fall apart either. And stockpiling of anything is a definite "no-no" in their eyes

      But you also need to convince people that pandemics are neither blue nor red. Its neither D nor R. This is the real reason Asian countries did better. They just put their masks on and went on about their normal business. Their was no talk of loss of freedumbs. They just wore the masks

      Now that we are re-opening I wonder just how bad our next surge will be. I believe that ANY building that is LESS than 20 years old will have outbreaks Why? Their AC systems were designed to operate with lower demand for power for energy savings. They computerized design with the main parameters being lowered cost, with as much comfort as possible. No where in a new AC system is airflow "treatment" a "thing" to consider. Crissa mentioned that plexiglass shields create eddies of airflow. They also completely demolish the efficiencies built into the heating and AC system. Will we learn from this? I doubt it. Pandemics are few and gar between so making grossly expensive changes to building system designs won't happen

      But if people have no hesitation about masking and keeping our distance then we could minimize the spread of MANY diseases. And we would have to remove POLITICS from THAT discussion. When people come to the conclusion that public health SHOULD no be politicized, we will be much better prepared

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