The table showing mask effectiveness was enough for me to go out and grab a stack of N95s. I had been wearing multi-layer cloth masks, but if N95s are that much better, then I'm convinced.
For the mask chart - what are the parameters of people's exposure with these varying levels of protection? For example, are they indoors? Well ventilated, or not? How far apart are they from each other? I'm hoping to understand the context better, because this chart fuels either "everyone needs K/N 95" or "masks don't work".
Looking at that table from the WSJ, it takes 15 minutes for my kid to be infected in school without masks, but if they don their paw patrol masks, he gets an extra 12 minutes until infected? But maybe up to an hour if we swap to surgical masks?
School is 7 hours long.
Love your posts, but this particular issue doesn't make sense. Parents should be able to choose if their kids can enjoy school without masks and take the 15 minute risk over not seeing each other's faces for the extra 12-45 minutes of "protection".
Cherry picking means to pick in a highly selective manner to prop up your argument.
The overwhelming majority of children, I'd wager close to 100%, are not wearing fit tested sealed n95 respirators. I'm not even sure they make such a thing for children under 12. Almost all of them are in cloth or surgical (from my observations, heavily leans toward cloth).
There are 16 tiles in that graph. 15 of them provide protection for less than a single school day. 8 of them less than a single class period. The most common masks worn fall within the 40 minute boundary. You cherry picked the single tile which excludes almost all real-world children
Yes.... and no. A recent study in Iowa, cited by CDC, suggests relatively close exposure yields infection a little less than 27% of the time (note that this was pre-omicron; most likely the number is at least twice that now) and that if both parties to such interaction were masked, the ratio infected dropped to slightly over 12%, or, less than half. What it becomes, then, is what we ALWAYS have when we invoke statistics in public health: A gambling opportunity pitting exposure time vs number infected but with a bias inserted.
Reducing the risk by over 50% is pretty big. When the goal is risk reduction, and we have real-world evidence that masks help, we need to look at this, and consider it.
The know the actual gambling odds I think we have to know the following (please correct/update me if I have anything wrong/missing):
1) The # of virions to cause infection. For other respiratory diseases I have seen this be listed somewhere between 10-100. Do we truly know what it is for Covid?
2) The # of virions expelled by someone contagious. I've seen estimates of 10,000 - 100,000 per minute. The type of activity certainly plays a role (singing > breathing for example)
3) The lifespan and mechanics of virions once emitted - since we realized it was airborne I am seeing estimates that the virions survive in the air 12-16 hours just floating around.
4) The actual size of the virions particulate we are dealing with here. Large number of pro mask studies keep citing the < 5 micron baseline, but the viruses themselves can be 30,000x smaller than that (for reference the micropore in n95 is 8 micron). What are we actually dealing with here in terms of particle size we need to filter out?
Tying it all together - suppose we had a contagious person, and we left them in a room for 1 hour. Do we have a way to calculate and truly "know" how many virions are floating around the room and what size they are?
Anyway, if you have the link to the Iowa study referenced by CDC post the link - I don't think I have that one and a quick google wasn't turning up anything recent. Thanks.
I’ll have to look for the MMWR info on the Iowa study… tomorrow.
We’re probably in the 10-100 virons range for infection. What is different in first delta and then omicron is the number of reproduction capable particles is significantly higher than earlier variants with delta producing around 30x more virons, and omicron on the order of 70x.
Early studies on virus lifespan that I’ve seen were on surfaces, and appeared to have been decidedly conservative, in that the estimates were some what longer than expected. I suspect a well-hydrated particle residing on an aerosol droplet can survive at least 18 hours. The question, then, is how does air circulation and filtration affect aerosol deposition or removal, or droplet aggregation and dropout.
I’ll bypass the actual particle size but address the mask issue. Well-designed masks are multilayer, and some of the medical masks employ electrostatic charge using dissimilar fabrics to trap aerosols and particulates within layers. So… the actual particle size is more a diversion than a direct issue.
A better mechanical engineer than I will have to calculate the aerosol load for your hypothetical room that has been contaminated by your hypothetical patient.
1) there is not a predictable number of virons (ranging from 0 to ~a million), nor 2) a uniform distribution of fomite sizes resulting from singing, a cough, a sneeze, normal breathing, heavy exertion, etc., (nor for any single one of these sources, nor across time, even within a single person).
3) Virons may ride enormously different sized fomites, 4) some fomites may include significant moisture and protein (aka 'snot', etc.) that will resist desiccation and inactivation, and others will have meaningfully less, 5) some will be in spaces with hard UV, some not, 6) the ambient temperature and humidity can range largely from those that preserve or harm the viron, 7) some will fall rapidly from gravity, and some will remain in aerosol for hours, 8) the number of virons per fomite will be greater (all these other things equal) for larger fomites, but will not remain in the air as long, 9) even if a viron is small relative to gaps through a mask, at such small dimensions 'stickyness' of viron (due to electrostatic conditions or moisture, etc) is a significant factor in filtration, 10) 'my pandemic' was HIV, and I recall a South African study that estimated it took 4 viruses on average in the blood stream, for 1 to get successfully into a cell and start reproducing, and it took perhaps thousands in the cecum (perhaps just a few tries, depending on MANY factors) or millions in the mouth (many tries, depending on MANY factors), to produce successful HIV transmission. In short, knowing the number in the air is such a small part of the LONG voyage of statistical transmission that it tells little, alone.
All these factors can interact in ways that are not yet studied, since a) it is very hard, and b) it would take very much money, very many studies, and more time than people are willing to allow, to study all the permutations and combinations of these many factors - either as an 'average' or as a specific stipulated situation.
When one doesn't know, either one gambles with children if one is arrogant, or one is careful until there have been sufficient experiments of nature in places that choose less conservative health protections, to allow one to be more confident about being less conservative with children's health. For some, including a 21 yo guest in my household, long covid effects can happen without any awareness or symptoms of the acute disease, as is the common case in children. They get infected at similar rates, but manifest (acute) illness at much lower rates. What is unknown, is the long term cost - will they have early dementia?
NO ONE KNOWS, any more than one knows about the long term effects of iPhone use, or a year of school closure.
So yeah, I masked when I walked the TB wards and HIV wards in Africa, and when I did surgery I double gloved. And I took my son out of school for 12 months until other people with less concern, and much less knowledge, tested the waters to my satisfaction that the data showed diminishing returns for social distancing after vaccine and with mask.
We continued to test and mask longer than most. My son transitioned from in school to a front-line worker. We tested often (over 50 kits) and upon indication. We happen to have access to PCR at home. Neither of us have had covid-19 so far (I had the antibody test that researchers use to determine 'ever infected', since I could, and was curious/surprised, and knew to how to get this test).
I'm one of the rare folk (17 in a 1,000,000 last I checked) who had pericarditis and myocarditis after my 2nd and 3rd vaccination, so only my son, whom I live with, continues with vaccination (and I thank him for his consideration).
The symptoms of post-jab pericarditis closely matched an episode of 'devil's grippe' / Barnholmes disease / infectious pleurodynia that I had in 2000 in Zambia (due to Coxsackie B3 virus infection - ironically contracted at the Annual APHA meeting in NYC the week before (Nov 2000)), that I took CB3V antibody titers before and after my third Covid vaccination. And you guessed it - they spiked with my second pericarditis - but not until after they took out my appendix due to the indeterminate cause of pain in the early course of the pericarditis and a red herring of a fecalith.
So, I suspect that in some number of cases greater than mine alone, that the rare myocarditis and pericarditis associated with Covid vaccine has to do less with the vaccine alone, and more with a rare immunological interaction of a vaccine triggering antibodies to a prior (CBV?) infection - one which, in my case, caused pleuritis and pericarditis (and put me in ICU in Pretoria, where I was medivac'd) back in 2000.
The vaccine is definitely worth taking; more people are seriously harmed by not having it, than by having it, even though no vaccine is risk free & there are RARE exceptions where if one could knew in advance the result one would decline it. I'm one, but my situation is about as far from standard as one can get. Many things we can't know in advance (or at all), so we play the odds as best we can...
This means we follow expert advice about when and whether to vaccinate. I've travelled a LOT, spent years in hundreds of hospitals around the world, & can list over 50 vaccinations I've had. I'm currently a healthy 70 yo, and a sample size of one, your mileage may vary.
Lastly, yes, I expect that (at most) one person will read this, Gerry. But it takes just one exposure to have a 'viral moment' - Or an incurable virus.
Took me close to a week, but finally got time to review this. Thanks for sharing.
Quick thoughts:
1) It's a retrospective case control study done by way of questionnaire and relies heavily on memory. These are among the weakest forms of evidence.
2) According to their findings in Table 1 the best odds of not getting covid is the index patient NOT wearing a mask and only the contact person to wear a mask, which gives odds of 10%. If instead the person who is actually sick wears the mask and the contact does not wear the mask, the odds rise to 29%. If they both take off their masks the odds lower to 26%. That gives indication of the quality of data they gleaned.
3) Outside of the study, on February 10 Iowa's governor lifted the mask mandate to which The Washington Post reported "Welcome to Iowa, a state that doesn’t care if you live or die" [1] - however, cases would continue to drop in Iowa for 5 straight months despite the lifting of mask mandate (and other restrictions).
4) "Among the limitations to this study is that many persons could not be contacted or declined to cooperate with public health investigations. There are almost certainly substantial differences between case-patients and contacts that we were able to interview and those who declined to provide information or were unable to be reached"
It's possible and often likely that the type of people who answer these surveys, respond to health officials are "people pleasers" that want to help and unwittingly tell the interviewer what they want to hear. Which is why these sorts of studies are at the lowest end of evidence.
Not attacking the messenger Gerry - I appreciate you sharing as this is one I missed somehow. Thanks for sharing.
If masking reduces infection by 53% would we expect to see about 53% fewer cases in an area that masks all the time versus a similar area that doesn’t mask at all? (Assuming demographics are similar)
That table is from Spring 2021, so I think pre-Delta, even. What is the divisor because R0 is much larger for Omicron? If Omicron R0=5.0, and original variant on which this is based was 1.0 (i.e. 1/5), then for example, is 15 minutes for no masks really = 15/5 = 3 minutes?
I love this chart showing the length of time for risk of exposure per varying masks, but when I looked closely I realized it is based on PRE-Omicron studies. In fact, that 15 minutes info is from the very first variant. I wonder what an up-to-date chart would look like?
Has there been any research on Long Covid and vaccination status? We're curious how protected we might be IF we contract Omicron (AZ, PZ, PZ or PZx2+booster). Thanks
Yes, I'm the same. I know that you have posted that long Covid is less likely in those who are vaccinated, but the risk isn't low enough for my taste, given my belief that my pre-existing condition likely predisposes me to long Covid. I'm sure it's too early to know, but I'm hoping to see numbers about the risk of long Covid from Omicron for fully vaxxed folks.
Thank you for your insights on this mess we find ourselves in. There have been other intriguing mitigation strategies that have just not been considered for further testing. For example, did you ever read that study on that virus-killing polypeptide nasal spray? It was tested in ferrets and was found to stop COVID transmission, but it never made it to market. I would have totally bought it if it did. I have a PhD in Immunology, so I keep my ear to the ground and I stumbled on something similar - monolaurin (lauricidin) isolated from coconut oil, which disrupts the viral envelope, so it kills all enveloped viruses in vitro. A scientist at the University of Iowa tested it in human volunteers; his readout measure was a reduction in Staph aureus levels when applied as a nasal gel to the anterior nares (it also kills certain bacteria). I got the recipe from him and made it (and have been using it for about a year now). It's obviously safe, but I have no idea how effective. I would LOVE to know. If it reduces transmission to a degree (chances are it will), it will atleast help at the times that our masks need to be off to eat/drink. Plus it's a layer bolstering the other somewhat, but not fully effective layers of protection we don. There was also a study in Nature that showed that higher blood levels of monolaurin correlated with protection against COVID. While correlation is not causation, all of this makes you wonder and also bang your head in frustration that further studies are not being done. The scientist met many dead ends with funding support, in this messed-up, bewildering world we live in, where strategies to reduce transmission of ALL variants and other enveloped respiratory viruses are not even considered for further testing. I've written a blog referencing the studies I mention on this (and the recipe for the nasal gel) in case anyone is interested (next comment). It's safe to use and cheap to make, so it goes to my Hail Mary pile of strategies to stay safe, that supplement all the recommended ones (vaccinating, boosting, masking).
I would love to know if anyone else has tried this -- I don't know if the gel would really work for me since I blow my nose so frequently (sinus issues), but maybe the internal ingestion of the capsules?
Monolaurin first came on my radar because of someone in my neighborhood group claiming that everyone in his household had been exposed to COVID, but he and another family member taking monolaurin orally were the only ones not to test positive/have symptoms. I did not beleive that taking monolaurin orally would help, though I can see how the nose gel might provide some protection, and was willing to try that.
But now, after reading the Nature study, I think it's *maybe* possible that even oral consumption of monolaurin may help. It can't really hurt - I'd read the reviews on Amazon. Like I said, we can never know for sure if it helps and to what degree until well-designed large-scale studies are done, and it's INFURIATING that they are not being done. I'd be willing to crowdfund them for sure.
Quite a few people following my blog have tried the gel. Monolaurin is a fat-like molecule, and given how vascular the anterior nares are, it's possible that applying the gel daily causes a local increase in monolaurin levels in the cells of nasal epithelium, and this forms part of the protection as these are the first cells to encounter the virus. This is just merely speculation on my part though.
Thank you! I'm curious about the WSJ mask table. I've been hearing for a while that wearing a mask protects others from you, more than it protects you (though it does both). But this table is symmetric, so shows the same level of protection regardless of who is wearing the mask. Is this oversimplified, or is it truly symmetric?
Is that chart up to date??? It says Spring 2021, but we are in 2022 now with a few variants out since. What variant does that chart relate to? That chart is exactly what I have been looking for but updated/current situation.
Yes, Omicron spreads faster, much faster but if one is going to post a chart like this it should be current to not give out false info as this chart is not related to todays world, but almost a year ago. So you say the numbers would be lower with Omicron which is very true, but how much lower??? What is that info??
Unfortunately, there is no second booster on the "schedule" right now, no talk about it.. Just Israel is giving it in their country to those 60 and over. I wish the US would allow an optional second booster for those of us that got it late summer early fall as they say your protection lowers significantly after 10 weeks :(
I'm still pretty skeptical of some of the Israeli work to date. And, I'm concerned about frequent boosters and the effect on the immune system. Right now, the evidence supporting Yet Another Booster seems a bit thin, but this could change with a couple of really good lab studies.
but is there any scientific data behind the shortening of the quarantine time from 10 to 5 days? was there ever any scientific data behind excluding classrooms from contact tracing? my kid's school is using the exception from contact tracing to refuse to let families know if someone in their kid's classroom tests positive.
@Katelyn, thoughts on the use of (K)N95s in the general public? On the pro side, better filtreation. On the con side, proper fitting is difficult, and in general terms, a well-fitting N95.... hurts when worn for long periods. I'm not sure they're going to work well for the public.
Dr Jetelina - I hope this message finds you. I am a subscribing member but not aware of how to send questions to you directly. Really appreciate this flow chart regarding masking and isolation. Thank you. I have 2 subjects I am very eager for your input on. 1) Can you give an update about the Moderna trials for kids especially 6mth-5year. I hear there is some promise here that will be faster than waiting on the Pfizer "re-do". 2) Can you shed some light on when the CDC will update the guidance for DAYCAREs and school facilities with quarantining. I know its at the state level by my state (IL) is waiting for CDC and currently their documentation still says any EXPOSURE positive or not...testing or not... requires all children "exposed" home for 14 days AND we pay for it! Why has the CDC reduced quarantine for even the unvaccinated but children have their routines destroyed and parents cant work... its a nightmare! Do you see any end to this?? Thank you for all you do! You have been a godsend!!!
Sorry to get all personal, but do you make more than $50k a year?
That’s all I make, and I pulled my kids. Not having to panic while waiting for someone to address your acute angle of a concern, is worth burning the money alone. If you’re over 6 figures, quit wasting time/energy with your questions…
Pull ‘em and be happy you still can. Whatever “I pay for it” costs.
Parents are in an impossible position right now. You made your decisions based on your family's needs and other parents are struggling to do the same for their families. Please choose compassion rather than coming here to play the misery olympics. Fwiw, I am very sorry for your struggles and don't think you (nor any of us) should have had to face these choices.
Sounds to me like you prefer to encumber our precious time/space with an epidemiologist as though she were your private math tutor, asking her to answer your personal economic calculus (especially obnoxious given the likely affluence of most on here).
Please choose to ask questions all of us could utilize the answers to.
I ain’t struggling. I’m free and easy and not fretting my time away, self-employment pays in ways worth more than money.
Eli, you've got to decide when to pull your kids, and when not to. At this point, most states' leaders want the schools open at any cost: We're unlikely to see blanket shut-down orders, although some school districts either have the leeway or don't care about governors' or legislative mandates and make decisions to close based on something approaching public health guidance. Unfortunately, beginning at the start of this pandemic, messaging was that the business/economic success was more important than individuals' health, and it's become impossible to reverse that messaging reliably.
Actually, I find that I agree with both of you, but I don't know enough to pass any judgments (and wouldn't in any event). Suffice it to say that a lot of legislators in our majority part would rather abolish public schools and give every kid a voucher. They refer to public schools as "government schools." The state's response to masks in schools was to make it a matter of local control. That meant that in many districts masks were at least discouraged because parents didn't like them. Kids paid the price for. That was due to their parents political views, not the sound judgments of educators.
Thanks for the input, but I clearly stated that I pulled my kid already.
Read other people’s posts much? Or just come here to pedant (yeah, I made it a verb)?
I’d rather be a poor carpenter taking care of my own kid than some corporate automaton too cheap to cash out sick days to spare my kid, spending my time and energy petitioning an epidemiologist to answer my personal crises.
On a side note, your posts have useful information/perspective, so thank you. Sincerely.
I realized before that you'd made your decision. I was making what I thought was an affirming statement, but it was also generalized for other readers. In the past, as a working dad, I took time off when I could as my wife's clinical schedule was a bit less forgiving, so I do understand.
I do try to provide solid info here. Katelyn provides excellent material, but sometimes I can answer questions for folks. She and I tend to read the same literature, so I'm usually able to keep up.
Thanks for the kind words on the side note. Just trying to help.
I've not seen anything from Moderna lately on their ongoing trials. They'll release something when they get results, but if they follow the rule book, nothing prematurely.
CDC will update their guidance, most likely, when they get around to it. I believe the stated if not published recommendation for exposure in schools is now 10 days, however.
CDC continues to suffer from communications problems, even if most of their decisions appear to have a better science basis than in the recent past.
Can you comment on data indicating flu deaths have dropped by somewhere like 75% during the covid era? There are several reasons that might contribute to this, but if masks etc are the main reason, is it reasonable to use that to extrapolate what the covid deaths might have been without masking/distance/shutdowns? My back of envelope suggests over 3 million - and that is separate from any vaccine effect.
For scenario yellow (vaxxed but not boosted), what if you completed the primary series of Pfizer or Moderna LESS than 6 months ago. There is no option for this on the chart. Is it the Green arrows, No Quarantine?
And there's at least one other logic problem with that flow chart. Surely someone has pointed it out to the Maine CDC by now? It's still live on their website though.
The table showing mask effectiveness was enough for me to go out and grab a stack of N95s. I had been wearing multi-layer cloth masks, but if N95s are that much better, then I'm convinced.
For the mask chart - what are the parameters of people's exposure with these varying levels of protection? For example, are they indoors? Well ventilated, or not? How far apart are they from each other? I'm hoping to understand the context better, because this chart fuels either "everyone needs K/N 95" or "masks don't work".
Looking at that table from the WSJ, it takes 15 minutes for my kid to be infected in school without masks, but if they don their paw patrol masks, he gets an extra 12 minutes until infected? But maybe up to an hour if we swap to surgical masks?
School is 7 hours long.
Love your posts, but this particular issue doesn't make sense. Parents should be able to choose if their kids can enjoy school without masks and take the 15 minute risk over not seeing each other's faces for the extra 12-45 minutes of "protection".
If I were to cherry-pick from the graph, I could tell you that masks can allow for 2,500 hours of protection. That’s 357 seven-hour school days.
Cherry picking means to pick in a highly selective manner to prop up your argument.
The overwhelming majority of children, I'd wager close to 100%, are not wearing fit tested sealed n95 respirators. I'm not even sure they make such a thing for children under 12. Almost all of them are in cloth or surgical (from my observations, heavily leans toward cloth).
There are 16 tiles in that graph. 15 of them provide protection for less than a single school day. 8 of them less than a single class period. The most common masks worn fall within the 40 minute boundary. You cherry picked the single tile which excludes almost all real-world children
Also, please, you’ve lost those of us without the time/resources you have to write many words…
What’s your point exactly?
I lost interest in what you were saying.
Uh, huh. You seem to know a lot about cherry picking. Can you please tell me more?
Yes.... and no. A recent study in Iowa, cited by CDC, suggests relatively close exposure yields infection a little less than 27% of the time (note that this was pre-omicron; most likely the number is at least twice that now) and that if both parties to such interaction were masked, the ratio infected dropped to slightly over 12%, or, less than half. What it becomes, then, is what we ALWAYS have when we invoke statistics in public health: A gambling opportunity pitting exposure time vs number infected but with a bias inserted.
Reducing the risk by over 50% is pretty big. When the goal is risk reduction, and we have real-world evidence that masks help, we need to look at this, and consider it.
The know the actual gambling odds I think we have to know the following (please correct/update me if I have anything wrong/missing):
1) The # of virions to cause infection. For other respiratory diseases I have seen this be listed somewhere between 10-100. Do we truly know what it is for Covid?
2) The # of virions expelled by someone contagious. I've seen estimates of 10,000 - 100,000 per minute. The type of activity certainly plays a role (singing > breathing for example)
3) The lifespan and mechanics of virions once emitted - since we realized it was airborne I am seeing estimates that the virions survive in the air 12-16 hours just floating around.
4) The actual size of the virions particulate we are dealing with here. Large number of pro mask studies keep citing the < 5 micron baseline, but the viruses themselves can be 30,000x smaller than that (for reference the micropore in n95 is 8 micron). What are we actually dealing with here in terms of particle size we need to filter out?
Tying it all together - suppose we had a contagious person, and we left them in a room for 1 hour. Do we have a way to calculate and truly "know" how many virions are floating around the room and what size they are?
Anyway, if you have the link to the Iowa study referenced by CDC post the link - I don't think I have that one and a quick google wasn't turning up anything recent. Thanks.
I’ll have to look for the MMWR info on the Iowa study… tomorrow.
We’re probably in the 10-100 virons range for infection. What is different in first delta and then omicron is the number of reproduction capable particles is significantly higher than earlier variants with delta producing around 30x more virons, and omicron on the order of 70x.
Early studies on virus lifespan that I’ve seen were on surfaces, and appeared to have been decidedly conservative, in that the estimates were some what longer than expected. I suspect a well-hydrated particle residing on an aerosol droplet can survive at least 18 hours. The question, then, is how does air circulation and filtration affect aerosol deposition or removal, or droplet aggregation and dropout.
I’ll bypass the actual particle size but address the mask issue. Well-designed masks are multilayer, and some of the medical masks employ electrostatic charge using dissimilar fabrics to trap aerosols and particulates within layers. So… the actual particle size is more a diversion than a direct issue.
A better mechanical engineer than I will have to calculate the aerosol load for your hypothetical room that has been contaminated by your hypothetical patient.
This public press article by the Guardian (https://www.theguardian.com/world/2022/jan/11/covid-loses-90-of-ability-to-infect-within-five-minutes-in-air-study) and the base research preprint (https://www.medrxiv.org/content/10.1101/2022.01.08.22268944v1.full.pdf) are pertinent. Bottom line: If this research bears out, SARS-CoV-2 loses up to 90% of its infectiousness as an aerosol in short order once released. This is good news overall, and all the more reason for maintaining good-quality masking.
1) there is not a predictable number of virons (ranging from 0 to ~a million), nor 2) a uniform distribution of fomite sizes resulting from singing, a cough, a sneeze, normal breathing, heavy exertion, etc., (nor for any single one of these sources, nor across time, even within a single person).
3) Virons may ride enormously different sized fomites, 4) some fomites may include significant moisture and protein (aka 'snot', etc.) that will resist desiccation and inactivation, and others will have meaningfully less, 5) some will be in spaces with hard UV, some not, 6) the ambient temperature and humidity can range largely from those that preserve or harm the viron, 7) some will fall rapidly from gravity, and some will remain in aerosol for hours, 8) the number of virons per fomite will be greater (all these other things equal) for larger fomites, but will not remain in the air as long, 9) even if a viron is small relative to gaps through a mask, at such small dimensions 'stickyness' of viron (due to electrostatic conditions or moisture, etc) is a significant factor in filtration, 10) 'my pandemic' was HIV, and I recall a South African study that estimated it took 4 viruses on average in the blood stream, for 1 to get successfully into a cell and start reproducing, and it took perhaps thousands in the cecum (perhaps just a few tries, depending on MANY factors) or millions in the mouth (many tries, depending on MANY factors), to produce successful HIV transmission. In short, knowing the number in the air is such a small part of the LONG voyage of statistical transmission that it tells little, alone.
All these factors can interact in ways that are not yet studied, since a) it is very hard, and b) it would take very much money, very many studies, and more time than people are willing to allow, to study all the permutations and combinations of these many factors - either as an 'average' or as a specific stipulated situation.
When one doesn't know, either one gambles with children if one is arrogant, or one is careful until there have been sufficient experiments of nature in places that choose less conservative health protections, to allow one to be more confident about being less conservative with children's health. For some, including a 21 yo guest in my household, long covid effects can happen without any awareness or symptoms of the acute disease, as is the common case in children. They get infected at similar rates, but manifest (acute) illness at much lower rates. What is unknown, is the long term cost - will they have early dementia?
NO ONE KNOWS, any more than one knows about the long term effects of iPhone use, or a year of school closure.
So yeah, I masked when I walked the TB wards and HIV wards in Africa, and when I did surgery I double gloved. And I took my son out of school for 12 months until other people with less concern, and much less knowledge, tested the waters to my satisfaction that the data showed diminishing returns for social distancing after vaccine and with mask.
We continued to test and mask longer than most. My son transitioned from in school to a front-line worker. We tested often (over 50 kits) and upon indication. We happen to have access to PCR at home. Neither of us have had covid-19 so far (I had the antibody test that researchers use to determine 'ever infected', since I could, and was curious/surprised, and knew to how to get this test).
I'm one of the rare folk (17 in a 1,000,000 last I checked) who had pericarditis and myocarditis after my 2nd and 3rd vaccination, so only my son, whom I live with, continues with vaccination (and I thank him for his consideration).
The symptoms of post-jab pericarditis closely matched an episode of 'devil's grippe' / Barnholmes disease / infectious pleurodynia that I had in 2000 in Zambia (due to Coxsackie B3 virus infection - ironically contracted at the Annual APHA meeting in NYC the week before (Nov 2000)), that I took CB3V antibody titers before and after my third Covid vaccination. And you guessed it - they spiked with my second pericarditis - but not until after they took out my appendix due to the indeterminate cause of pain in the early course of the pericarditis and a red herring of a fecalith.
So, I suspect that in some number of cases greater than mine alone, that the rare myocarditis and pericarditis associated with Covid vaccine has to do less with the vaccine alone, and more with a rare immunological interaction of a vaccine triggering antibodies to a prior (CBV?) infection - one which, in my case, caused pleuritis and pericarditis (and put me in ICU in Pretoria, where I was medivac'd) back in 2000.
The vaccine is definitely worth taking; more people are seriously harmed by not having it, than by having it, even though no vaccine is risk free & there are RARE exceptions where if one could knew in advance the result one would decline it. I'm one, but my situation is about as far from standard as one can get. Many things we can't know in advance (or at all), so we play the odds as best we can...
This means we follow expert advice about when and whether to vaccinate. I've travelled a LOT, spent years in hundreds of hospitals around the world, & can list over 50 vaccinations I've had. I'm currently a healthy 70 yo, and a sample size of one, your mileage may vary.
Lastly, yes, I expect that (at most) one person will read this, Gerry. But it takes just one exposure to have a 'viral moment' - Or an incurable virus.
https://wwwnc.cdc.gov/eid/article/28/1/21-1591-t3
Took me close to a week, but finally got time to review this. Thanks for sharing.
Quick thoughts:
1) It's a retrospective case control study done by way of questionnaire and relies heavily on memory. These are among the weakest forms of evidence.
2) According to their findings in Table 1 the best odds of not getting covid is the index patient NOT wearing a mask and only the contact person to wear a mask, which gives odds of 10%. If instead the person who is actually sick wears the mask and the contact does not wear the mask, the odds rise to 29%. If they both take off their masks the odds lower to 26%. That gives indication of the quality of data they gleaned.
3) Outside of the study, on February 10 Iowa's governor lifted the mask mandate to which The Washington Post reported "Welcome to Iowa, a state that doesn’t care if you live or die" [1] - however, cases would continue to drop in Iowa for 5 straight months despite the lifting of mask mandate (and other restrictions).
4) "Among the limitations to this study is that many persons could not be contacted or declined to cooperate with public health investigations. There are almost certainly substantial differences between case-patients and contacts that we were able to interview and those who declined to provide information or were unable to be reached"
It's possible and often likely that the type of people who answer these surveys, respond to health officials are "people pleasers" that want to help and unwittingly tell the interviewer what they want to hear. Which is why these sorts of studies are at the lowest end of evidence.
Not attacking the messenger Gerry - I appreciate you sharing as this is one I missed somehow. Thanks for sharing.
[1] https://www.washingtonpost.com/outlook/2021/02/10/iowa-lift-all-restrictions/
If masking reduces infection by 53% would we expect to see about 53% fewer cases in an area that masks all the time versus a similar area that doesn’t mask at all? (Assuming demographics are similar)
That table is from Spring 2021, so I think pre-Delta, even. What is the divisor because R0 is much larger for Omicron? If Omicron R0=5.0, and original variant on which this is based was 1.0 (i.e. 1/5), then for example, is 15 minutes for no masks really = 15/5 = 3 minutes?
that's exactly right. i would estimate it's about 5 minutes. but even with just masks, the "real world" is far more complicated
I love this chart showing the length of time for risk of exposure per varying masks, but when I looked closely I realized it is based on PRE-Omicron studies. In fact, that 15 minutes info is from the very first variant. I wonder what an up-to-date chart would look like?
Has there been any research on Long Covid and vaccination status? We're curious how protected we might be IF we contract Omicron (AZ, PZ, PZ or PZx2+booster). Thanks
YES. This is one of my major concerns -- I already have my fill of chronic conditions, and I'd prefer not to add on!
Yes, I'm the same. I know that you have posted that long Covid is less likely in those who are vaccinated, but the risk isn't low enough for my taste, given my belief that my pre-existing condition likely predisposes me to long Covid. I'm sure it's too early to know, but I'm hoping to see numbers about the risk of long Covid from Omicron for fully vaxxed folks.
I'm also wondering about the risk of getting it through the eyes.
Yes, no one talks about eyes either! (I'm also chronically ill w/some symptoms already like long covid)
Thank you for your insights on this mess we find ourselves in. There have been other intriguing mitigation strategies that have just not been considered for further testing. For example, did you ever read that study on that virus-killing polypeptide nasal spray? It was tested in ferrets and was found to stop COVID transmission, but it never made it to market. I would have totally bought it if it did. I have a PhD in Immunology, so I keep my ear to the ground and I stumbled on something similar - monolaurin (lauricidin) isolated from coconut oil, which disrupts the viral envelope, so it kills all enveloped viruses in vitro. A scientist at the University of Iowa tested it in human volunteers; his readout measure was a reduction in Staph aureus levels when applied as a nasal gel to the anterior nares (it also kills certain bacteria). I got the recipe from him and made it (and have been using it for about a year now). It's obviously safe, but I have no idea how effective. I would LOVE to know. If it reduces transmission to a degree (chances are it will), it will atleast help at the times that our masks need to be off to eat/drink. Plus it's a layer bolstering the other somewhat, but not fully effective layers of protection we don. There was also a study in Nature that showed that higher blood levels of monolaurin correlated with protection against COVID. While correlation is not causation, all of this makes you wonder and also bang your head in frustration that further studies are not being done. The scientist met many dead ends with funding support, in this messed-up, bewildering world we live in, where strategies to reduce transmission of ALL variants and other enveloped respiratory viruses are not even considered for further testing. I've written a blog referencing the studies I mention on this (and the recipe for the nasal gel) in case anyone is interested (next comment). It's safe to use and cheap to make, so it goes to my Hail Mary pile of strategies to stay safe, that supplement all the recommended ones (vaccinating, boosting, masking).
I would love to know if anyone else has tried this -- I don't know if the gel would really work for me since I blow my nose so frequently (sinus issues), but maybe the internal ingestion of the capsules?
Monolaurin first came on my radar because of someone in my neighborhood group claiming that everyone in his household had been exposed to COVID, but he and another family member taking monolaurin orally were the only ones not to test positive/have symptoms. I did not beleive that taking monolaurin orally would help, though I can see how the nose gel might provide some protection, and was willing to try that.
But now, after reading the Nature study, I think it's *maybe* possible that even oral consumption of monolaurin may help. It can't really hurt - I'd read the reviews on Amazon. Like I said, we can never know for sure if it helps and to what degree until well-designed large-scale studies are done, and it's INFURIATING that they are not being done. I'd be willing to crowdfund them for sure.
Quite a few people following my blog have tried the gel. Monolaurin is a fat-like molecule, and given how vascular the anterior nares are, it's possible that applying the gel daily causes a local increase in monolaurin levels in the cells of nasal epithelium, and this forms part of the protection as these are the first cells to encounter the virus. This is just merely speculation on my part though.
Here is the monolaurin gel recipe with the studies referenced, for anyone interested: https://smartsaversunite.com/my-monolaurin-experience/
Thank you! I'm curious about the WSJ mask table. I've been hearing for a while that wearing a mask protects others from you, more than it protects you (though it does both). But this table is symmetric, so shows the same level of protection regardless of who is wearing the mask. Is this oversimplified, or is it truly symmetric?
Is that chart up to date??? It says Spring 2021, but we are in 2022 now with a few variants out since. What variant does that chart relate to? That chart is exactly what I have been looking for but updated/current situation.
Thank you.
Alpha I believe. If you get past the paywall it mentions Omicron spreads faster so those numbers would be lower.
Yes, Omicron spreads faster, much faster but if one is going to post a chart like this it should be current to not give out false info as this chart is not related to todays world, but almost a year ago. So you say the numbers would be lower with Omicron which is very true, but how much lower??? What is that info??
I don't think they know. I found the source of the WSJ pictogram here:
https://www.acgih.org/covid-19-fact-sheet-worker-resp/
And the sources they list (for more than just this infographic) here:
https://www.acgih.org/covid19-references/#resp
My husband and I had our booster late august, is it time to get another for us .. I don’t seem to find the information I need on this
Unfortunately, there is no second booster on the "schedule" right now, no talk about it.. Just Israel is giving it in their country to those 60 and over. I wish the US would allow an optional second booster for those of us that got it late summer early fall as they say your protection lowers significantly after 10 weeks :(
I'm still pretty skeptical of some of the Israeli work to date. And, I'm concerned about frequent boosters and the effect on the immune system. Right now, the evidence supporting Yet Another Booster seems a bit thin, but this could change with a couple of really good lab studies.
but is there any scientific data behind the shortening of the quarantine time from 10 to 5 days? was there ever any scientific data behind excluding classrooms from contact tracing? my kid's school is using the exception from contact tracing to refuse to let families know if someone in their kid's classroom tests positive.
@Katelyn, thoughts on the use of (K)N95s in the general public? On the pro side, better filtreation. On the con side, proper fitting is difficult, and in general terms, a well-fitting N95.... hurts when worn for long periods. I'm not sure they're going to work well for the public.
Dr Jetelina - I hope this message finds you. I am a subscribing member but not aware of how to send questions to you directly. Really appreciate this flow chart regarding masking and isolation. Thank you. I have 2 subjects I am very eager for your input on. 1) Can you give an update about the Moderna trials for kids especially 6mth-5year. I hear there is some promise here that will be faster than waiting on the Pfizer "re-do". 2) Can you shed some light on when the CDC will update the guidance for DAYCAREs and school facilities with quarantining. I know its at the state level by my state (IL) is waiting for CDC and currently their documentation still says any EXPOSURE positive or not...testing or not... requires all children "exposed" home for 14 days AND we pay for it! Why has the CDC reduced quarantine for even the unvaccinated but children have their routines destroyed and parents cant work... its a nightmare! Do you see any end to this?? Thank you for all you do! You have been a godsend!!!
Sorry to get all personal, but do you make more than $50k a year?
That’s all I make, and I pulled my kids. Not having to panic while waiting for someone to address your acute angle of a concern, is worth burning the money alone. If you’re over 6 figures, quit wasting time/energy with your questions…
Pull ‘em and be happy you still can. Whatever “I pay for it” costs.
Parents are in an impossible position right now. You made your decisions based on your family's needs and other parents are struggling to do the same for their families. Please choose compassion rather than coming here to play the misery olympics. Fwiw, I am very sorry for your struggles and don't think you (nor any of us) should have had to face these choices.
Whatever.
Sounds to me like you prefer to encumber our precious time/space with an epidemiologist as though she were your private math tutor, asking her to answer your personal economic calculus (especially obnoxious given the likely affluence of most on here).
Please choose to ask questions all of us could utilize the answers to.
I ain’t struggling. I’m free and easy and not fretting my time away, self-employment pays in ways worth more than money.
Eli, you've got to decide when to pull your kids, and when not to. At this point, most states' leaders want the schools open at any cost: We're unlikely to see blanket shut-down orders, although some school districts either have the leeway or don't care about governors' or legislative mandates and make decisions to close based on something approaching public health guidance. Unfortunately, beginning at the start of this pandemic, messaging was that the business/economic success was more important than individuals' health, and it's become impossible to reverse that messaging reliably.
Actually, I find that I agree with both of you, but I don't know enough to pass any judgments (and wouldn't in any event). Suffice it to say that a lot of legislators in our majority part would rather abolish public schools and give every kid a voucher. They refer to public schools as "government schools." The state's response to masks in schools was to make it a matter of local control. That meant that in many districts masks were at least discouraged because parents didn't like them. Kids paid the price for. That was due to their parents political views, not the sound judgments of educators.
Thanks for the input, but I clearly stated that I pulled my kid already.
Read other people’s posts much? Or just come here to pedant (yeah, I made it a verb)?
I’d rather be a poor carpenter taking care of my own kid than some corporate automaton too cheap to cash out sick days to spare my kid, spending my time and energy petitioning an epidemiologist to answer my personal crises.
On a side note, your posts have useful information/perspective, so thank you. Sincerely.
It's enough to convince me that you put your kid ahead of a lot of other things. I wish we had a lot more of those where I am. I'll shut up.
I realized before that you'd made your decision. I was making what I thought was an affirming statement, but it was also generalized for other readers. In the past, as a working dad, I took time off when I could as my wife's clinical schedule was a bit less forgiving, so I do understand.
I do try to provide solid info here. Katelyn provides excellent material, but sometimes I can answer questions for folks. She and I tend to read the same literature, so I'm usually able to keep up.
Thanks for the kind words on the side note. Just trying to help.
I've not seen anything from Moderna lately on their ongoing trials. They'll release something when they get results, but if they follow the rule book, nothing prematurely.
CDC will update their guidance, most likely, when they get around to it. I believe the stated if not published recommendation for exposure in schools is now 10 days, however.
CDC continues to suffer from communications problems, even if most of their decisions appear to have a better science basis than in the recent past.
Can you comment on data indicating flu deaths have dropped by somewhere like 75% during the covid era? There are several reasons that might contribute to this, but if masks etc are the main reason, is it reasonable to use that to extrapolate what the covid deaths might have been without masking/distance/shutdowns? My back of envelope suggests over 3 million - and that is separate from any vaccine effect.
For scenario yellow (vaxxed but not boosted), what if you completed the primary series of Pfizer or Moderna LESS than 6 months ago. There is no option for this on the chart. Is it the Green arrows, No Quarantine?
And there's at least one other logic problem with that flow chart. Surely someone has pointed it out to the Maine CDC by now? It's still live on their website though.