If you want zero risk, wear an elastomeric respirator or DIY PAPR. Masks probably don’t work against the variants (masks wiped out the flu but not the massive fall/winter covid wave).
There’s no good evidence that outdoor transmission is even a thing, and mechanistic reasons (aerosols can’t accumulate outdoors) also cast doubt on the idea of outdoor transmission. In places where lots of people are vaccinated or have immunity by having been infected, the risk is miniscule even in outdoor crowds. If you’re extremely risk-averse, wear a respirator or PAPR or avoid crowds altogether.
Masks probably don’t work against the variants (masks wiped out the flu but not the massive fall/winter covid wave).
This seems like the wrong inference. The R0 of flu is something like 1.2, the R0 of Alpha was about 4 (at pre-COVID levels of social distancing). ‘Masks work’ looks like masks reducing R0 by some factor. If this reduces R0 to below 1, it wipes out the disease, if it remains above 1 you will still get a massive wave. Because the R0 of flu is so much lower, ‘flu was wiped out but COVID wasn’t’ is approximately 0 evidence about the effectiveness of masks.
For example, this paper found a 25% reduction in R0 from universal mask wearing. That would reduce flu to 0.9 and wipe it out, but reduce Alpha to 3, which is still very virulent. Yet, it is still obviously correct to wear a mask
It is obviously correct to wear a mask only if you do not have access to a respirator or PAPR.
Better protection could have wiped out covid just like masks wiped out the flu. While masks may have offered some better-than-nothing protection, it was grossly inadequate protection.
“Don’t work” seems like the wrong phrase. Unless the newer variants have evolved teleportation, masks will be about as effective as they ever were at reducing the extent to which respiratory droplets carry the virus from one person to another. I bet they produce about the same reduction in R as they used to.
Against newer more transmissible variants, widespread mask-wearing may not be enough to stop exponential growth among the unvaccinated. But “aren’t enough” and “don’t work” are two very different things.
“Don’t work” in the sense of “masks wiped out the flu but not the massive fall/winter covid wave.” One can argue that the last covid wave could have been worse without masks, but that’s pure speculation.
The newer variants might have defeated masks by producing more virus particles, for instance; no teleportation required. Whatever the mechanism, it seems clear that above a certain threshold of infectivity (compared to the original covid variants and last season’s flu variants), masks don’t work, or if you’re picky about it, masks don’t work that well.
Again, I don’t think it’s clear that “don’t work” is at all a good way to say it.
Consider the following scenario, which I expect has something like the right shape although all the concrete numbers are made up and probably wrong (and of course the numbers aren’t as deterministic as this makes it sound): the effect of wearing masks is that the number of virus particles you get hit with from being near someone infected is 3x lower; the likelihood of an infection taking hold is greater when the number of virus particles is larger; newer variants make infected people produce 2x more virus particles; maskless, the infection rate is high enough for exponential growth when the number of virus particles is >= half the number passed on (maskless) by the original variant.
Then (1) the original variant could be effectively stopped just by masks (you get N/3 virus particles, which is smaller than N/2); (2) the new variant can’t be (you get 2N/3 virus particles, which is larger than N/2); (3) the masks are still reducing virus transmission by the same factor as ever.
In this scenario the new variant needs something more than masks to stop it (e.g., more distancing, vaccination, testing-and-tracing). But that isn’t because masks don’t work any more, it’s because the new variant is worse and you need to do more to stop it.
It might turn out that if you pick any single intervention it “doesn’t work” with a newer more infective variant, if all you mean by that is that that intervention on its own isn’t enough to solve the problem. “Masks don’t work”, “distancing doesn’t work”, “contact tracing doesn’t work”, “vaccination doesn’t work”, and so on. Might as well give up, then: no point doing lots of things that don’t work. Except that they do work, but you need to do more than one of them at a time, and if you don’t use masks because “masks don’t work” then you need to do more of the other things instead.
It seems rather far from “pure speculation” to suggest that the last wave would have been worse without masks, given that it’s pretty well documented what masks do and how, and any increase in transmission makes things worse. (I mean, it could be that people would have reacted by being stricted about other safety measures like never leaving their homes, and that the net effect would have been to leave the number of cases about the same. But “number of cases about the same, because everyone inconvenienced themselves more” is one variety of “worse”.)
“Masks don’t work” would apply to a disease that spreads mostly by direct physical contact, or surface contamination. Masks don’t work against syphilis or tetanus. It’s incorrect, and irresponsible, to say that “masks don’t work” against a disease for which they do reduce transmission. If you think it’s plausible that they don’t in fact reduce transmission with newer strains of COVID-19, then present your evidence. (“People wore masks and there was still a wave of the disease” is not evidence[1].) Otherwise, I don’t think I’m the one who’s engaging in pure speculation.
[1] Of course strictly speaking it is evidence, in the same way that every time something happens that someone has prayed for it’s evidence for the existence of the god they prayed to, or every time someone rolls well in a game of backgammon it’s evidence that they have telekinetic powers. But like those things it’s weak evidence, because there are highly plausible scenarios in which those things happen even though the thing they’re meant to be evidence of isn’t so. You can get lucky when rolling dice. A disease can be infectious enough to spread even though masks help a lot in reducing transmission.
If the choice is between wearing a mask and nothing, wearing a mask would probably be better than nothing.
If the choice is between wearing a mask and a respirator or PAPR, choosing to wear a mask significantly increases risk, because we already know that masks offer poor protection. We know this because masks failed to stop the last covid wave.
In the wider context of covid waves: if everyone wore a respirator or PAPR starting before the last covid wave, covid would have been wiped out.
OK, sure: other more elaborate barriers between your face and the outside world are more effective than surgical masks, bits of cloth, etc. No question. But, again, the situation isn’t that masks don’t work. It’s that other things work even better.
(I would bet fairly heavily that surgical masks + full vaccination[1] are “enough”, given a modest level of general caution otherwise, even for the latest and most infectious strains. Surgical masks are much less hassle than respirators or PAPRs. I do not think I would recommend that fully vaccinated people who aren’t extra-vulnerable or extra-anxious should go out and get N95 respirators and the like rather than making do with masks.)
[1] With, say, Pfizer or Moderna or (less good but still probably enough) AstraZeneca. The same may be true for others but my ignorance about them is greater.
You need a model of the world that’s less black-and-white than “X works” versus “X doesn’tt work”. Any given intervention reduces transmission by a certain amount. Depending on how transmissible the currently-relevant strain of the virus is, different combinations of interventions will be sufficient or not. Collapsing all that to “works” versus “doesn’t work” is a bad idea; it makes it harder to think clearly.
At this point in the pandemic, the level of protection offered by masks is so uncertain (10% 1%? 0.1%?) and likely to be so small that masks are little more than a Hail Mary for those that don’t have access to vaccines, respirators, or PAPRs. While a Hail Mary doesn’t technically mean that it “doesn’t work,” it’s pretty close, and making a big deal about these distinctions is becoming a little pedantic.
For the vaccinated, recommending masks (which may or may not offer a tiny extra bit of protection) over vastly more effective respirators due to a small-to-none hassle factor seems a bit silly. It’s much more reasonable to recommend respirators or nothing.
You said something about “pure speculation” earlier, but I think that’s what you’re engaging in here.
What makes you think that masks offer “10%? 1%? 0.1%?” protection? Indeed, what do you mean by those numbers? What actual model of transmission leads you to think this?
[EDITED to add:] Actually, maybe I misunderstood you; is the “10%? 1%? 0.1%?” meant to be an amount of protection (in which case, why also say “and likely to be so small that …”—aren’t you saying the same thing twice?) or a probability of any protection at all (in which case, what are you smoking?)? Again, what actual model of transmission is this based on?
What masks do is to reduce the fraction (viruses breathed in) / (viruses breathed out), by blocking the passage of droplets or changing the pattern of air flow. Unless the later strains have evolved teleportation or something, it seems unlikely that the factor by which this fraction has reduced in any given situation is much different now from before. I’ve had trouble finding really convincing figures, but it seems like the typical factor for a surgical mask is somewhere on the order of a 3x-10x reduction in the “outward” direction, larger when speaking or coughing than when just breathing normally (which is good, because speaking and coughing make you emit a lot more viruses if infected). “Inward” protection seems to be somewhat less—maybe 2x? Home-made cloth masks appear to be substantially inferior to (ordinary, cheap) surgical masks.
This would mean e.g. that the amount of time you need to spend near an infected person in order to get infected yourself is 3-10x greater if they’re masked, 6-20x greater if you both are.
If you think that somehow none of this works any more because of the newer more infectious strains, or that it’s all nonsense and actually masks never had any substantial effect at all, then you should either give credible evidence that it doesn’t or explain a plausible way in which it would have stopped working (or would never have worked). “There was a wave of infections and masks didn’t stop it” is not credible evidence; that just means that the virus was infectious enough that whatever masks did wasn’t enough, which is perfectly consistent with masks doing a lot.
We know that masks have poor performance, because while masks seem to have eliminated the flu and to have stopped or significantly slowed down the spread of the original variants, especially in Asia, masks failed to have the same effect on the newer variants which caused the fall/winter wave. And since Delta is even more contagious than those variants, masks will be even less effective than they were during the last wave. How you can claim that this is not evidence is beyond me.
I also doubt that it’s useful or even possible to accurately calculate the efficacy of masks for the latest variants without doing lab work. How would you quantify the decrease in efficacy caused by increased infectivity due to better binding of the variants to human cells? How much more virus particles do these variants produce, if any, and how does that relate to mask efficacy? Is mask efficacy a spectrum or are there thresholds that suddenly render masks 0% effective in most or many situations? But since we already know that masks offer poor performance anyway, quantify exactly how poor the performance is (10%, 1%, 0.1%, or whatever) doesn’t seem to be all that important.
Masks have become a dangerous distraction from far more effective interventions.
You still seem to be assuming that “poor performance” = “not on their own sufficient to stop the latest variants growing exponentially”, and that is just unambiguously wrong.
Do you, or do you not, have any information that isn’t broadly consistent with the following crude model? 1. An infected person emits virus particles at some (somewhat random) rate, more when speaking or coughing than when breathing normally. 2. If you breathe in virus particles, there is some probability that you get infected; the probability is higher when the number of virus particles is higher. 3. If the infected person is wearing a mask, then the rate at which they emit virus particles is reduced by a constant factor somewhere in the vicinity of 5x. 4. If the not-yet-infected person is wearing a mask, then the number of virus particles reaching them is reduced by a constant factor somewhere in the vicinity of 2x. 5. Newer variants are more infectious, meaning some combination of (a) infected people emit more virus particles, or (b) the probability of infection for a given intake of virus particles is higher.
If this model is somewhere near the truth, then the only way for masks to be near-useless (“10%, 1%, 0.1%”, as you put it—but I asked you to explain what these numbers are supposed to mean and you didn’t, and I would still like you to) is if the newer variants cause such a colossal increase in the number of virus particles put out by an infected person, or in how effectively infectious they are, that being near them even briefly basically guarantees getting infected. Because otherwise, if you and they both wear masks then that means something like a 10x increase in how much exposure you can have before getting infected, and if the unmasked figure would be (say) 2 minutes’ conversation at a 2m distance, then that would turn into 20 minutes, and I at least have plenty of conversations that are longer than 2 minutes but shorter than 20 minutes.
Do you have good reason to believe that that model is far from the truth?
If not, do you have good reason to believe that the new variants are basically infinitely infectious?
If not, is there some other reason why the argument above fails?
Or have you just determined to keep saying “masks are useless” over and over, without ever making your claims precise enough to be evaluated, and without any actual model of how infection happens by which to justify your claim?
Once again, I appreciate that you are arguing for using something more effective than masks. I agree that things more effective than masks are more effective than masks. But it seems to me that you are either making almost certainly false claims about the effectiveness of masks (if you are saying that they aren’t what-I-call-effective, that they don’t substantially extend the range of what one can do without substantial risk of infection) or else using very misleading language to make the claims you are (if you are only saying that they are not sufficient on their own to stop a wave of Delta-variant COVID-19 -- which I agree is almost certainly the case), and I wish you wouldn’t do either of those things.
Given the fact that we already know that masks have poor performance based on the what I’ve already mentioned, models are pointless for most situations.
If you’re referring to modelling a strategy of maximizing personal (rather than public) protection with a poor performing tool, models could help you do that, but in the case of masks, it will turn out that most strategies are impractical because 1) there will be too many variables to keep track of, 2) some variables will be impossible or hard to obtain, and 3) some variables will be hard to control even with perfect knowledge. With or without a mask, if the distance between people is far enough, infection will be avoided regardless of infectivity due to dilution. If the distance is between two people, you may be able to calculate a minimum safe distance if you know all of the variables. Some of these variables are room size, ventilation, infectivity, mask type, rates of breathing and vocalization, and vaccination status. You’d also need to know if the room was previously occupied and by whom. Some of these these variables will be known but some will not be. You’ll also need to recompute these variables once they change. If you’re dealing with a simple model with two people in which nothing changes, this strategy might work. But real world cases are almost nothing like this. What if you go to another room or another person walks in? Is the ventilation the same? Is the person vaccinated? What kind of mask are they wearing? How many people were in the room before you walked in (aerosols can become suspended for hours even if the people that generated them are no longer around)? Modeling this stuff quickly becomes impractical, and if you can avoid that by wearing a respirator, why bother?
“10%, 1%, 0.1%” was meant to poke fun at the attempt of precisely quantifying the poor performance of masks and is not based on any data.
Thanks! I’m not particularly worried about outdoor things (though your comments on crowds help fill in a gap where I had some uncertainty). More curious whether to attend indoor events without a vaccination restriction.
If you want zero risk, wear an elastomeric respirator or DIY PAPR. Masks probably don’t work against the variants (masks wiped out the flu but not the massive fall/winter covid wave).
There’s no good evidence that outdoor transmission is even a thing, and mechanistic reasons (aerosols can’t accumulate outdoors) also cast doubt on the idea of outdoor transmission. In places where lots of people are vaccinated or have immunity by having been infected, the risk is miniscule even in outdoor crowds. If you’re extremely risk-averse, wear a respirator or PAPR or avoid crowds altogether.
This seems like the wrong inference. The R0 of flu is something like 1.2, the R0 of Alpha was about 4 (at pre-COVID levels of social distancing). ‘Masks work’ looks like masks reducing R0 by some factor. If this reduces R0 to below 1, it wipes out the disease, if it remains above 1 you will still get a massive wave. Because the R0 of flu is so much lower, ‘flu was wiped out but COVID wasn’t’ is approximately 0 evidence about the effectiveness of masks.
For example, this paper found a 25% reduction in R0 from universal mask wearing. That would reduce flu to 0.9 and wipe it out, but reduce Alpha to 3, which is still very virulent. Yet, it is still obviously correct to wear a mask
It is obviously correct to wear a mask only if you do not have access to a respirator or PAPR.
Better protection could have wiped out covid just like masks wiped out the flu. While masks may have offered some better-than-nothing protection, it was grossly inadequate protection.
Sure, I’d agree with this. Things like N95s and P100s are much better than cloth or surgical masks.
“Don’t work” seems like the wrong phrase. Unless the newer variants have evolved teleportation, masks will be about as effective as they ever were at reducing the extent to which respiratory droplets carry the virus from one person to another. I bet they produce about the same reduction in R as they used to.
Against newer more transmissible variants, widespread mask-wearing may not be enough to stop exponential growth among the unvaccinated. But “aren’t enough” and “don’t work” are two very different things.
“Don’t work” in the sense of “masks wiped out the flu but not the massive fall/winter covid wave.” One can argue that the last covid wave could have been worse without masks, but that’s pure speculation.
The newer variants might have defeated masks by producing more virus particles, for instance; no teleportation required. Whatever the mechanism, it seems clear that above a certain threshold of infectivity (compared to the original covid variants and last season’s flu variants), masks don’t work, or if you’re picky about it, masks don’t work that well.
Again, I don’t think it’s clear that “don’t work” is at all a good way to say it.
Consider the following scenario, which I expect has something like the right shape although all the concrete numbers are made up and probably wrong (and of course the numbers aren’t as deterministic as this makes it sound): the effect of wearing masks is that the number of virus particles you get hit with from being near someone infected is 3x lower; the likelihood of an infection taking hold is greater when the number of virus particles is larger; newer variants make infected people produce 2x more virus particles; maskless, the infection rate is high enough for exponential growth when the number of virus particles is >= half the number passed on (maskless) by the original variant.
Then (1) the original variant could be effectively stopped just by masks (you get N/3 virus particles, which is smaller than N/2); (2) the new variant can’t be (you get 2N/3 virus particles, which is larger than N/2); (3) the masks are still reducing virus transmission by the same factor as ever.
In this scenario the new variant needs something more than masks to stop it (e.g., more distancing, vaccination, testing-and-tracing). But that isn’t because masks don’t work any more, it’s because the new variant is worse and you need to do more to stop it.
It might turn out that if you pick any single intervention it “doesn’t work” with a newer more infective variant, if all you mean by that is that that intervention on its own isn’t enough to solve the problem. “Masks don’t work”, “distancing doesn’t work”, “contact tracing doesn’t work”, “vaccination doesn’t work”, and so on. Might as well give up, then: no point doing lots of things that don’t work. Except that they do work, but you need to do more than one of them at a time, and if you don’t use masks because “masks don’t work” then you need to do more of the other things instead.
It seems rather far from “pure speculation” to suggest that the last wave would have been worse without masks, given that it’s pretty well documented what masks do and how, and any increase in transmission makes things worse. (I mean, it could be that people would have reacted by being stricted about other safety measures like never leaving their homes, and that the net effect would have been to leave the number of cases about the same. But “number of cases about the same, because everyone inconvenienced themselves more” is one variety of “worse”.)
“Masks don’t work” would apply to a disease that spreads mostly by direct physical contact, or surface contamination. Masks don’t work against syphilis or tetanus. It’s incorrect, and irresponsible, to say that “masks don’t work” against a disease for which they do reduce transmission. If you think it’s plausible that they don’t in fact reduce transmission with newer strains of COVID-19, then present your evidence. (“People wore masks and there was still a wave of the disease” is not evidence[1].) Otherwise, I don’t think I’m the one who’s engaging in pure speculation.
[1] Of course strictly speaking it is evidence, in the same way that every time something happens that someone has prayed for it’s evidence for the existence of the god they prayed to, or every time someone rolls well in a game of backgammon it’s evidence that they have telekinetic powers. But like those things it’s weak evidence, because there are highly plausible scenarios in which those things happen even though the thing they’re meant to be evidence of isn’t so. You can get lucky when rolling dice. A disease can be infectious enough to spread even though masks help a lot in reducing transmission.
If the choice is between wearing a mask and nothing, wearing a mask would probably be better than nothing.
If the choice is between wearing a mask and a respirator or PAPR, choosing to wear a mask significantly increases risk, because we already know that masks offer poor protection. We know this because masks failed to stop the last covid wave.
In the wider context of covid waves: if everyone wore a respirator or PAPR starting before the last covid wave, covid would have been wiped out.
OK, sure: other more elaborate barriers between your face and the outside world are more effective than surgical masks, bits of cloth, etc. No question. But, again, the situation isn’t that masks don’t work. It’s that other things work even better.
(I would bet fairly heavily that surgical masks + full vaccination[1] are “enough”, given a modest level of general caution otherwise, even for the latest and most infectious strains. Surgical masks are much less hassle than respirators or PAPRs. I do not think I would recommend that fully vaccinated people who aren’t extra-vulnerable or extra-anxious should go out and get N95 respirators and the like rather than making do with masks.)
[1] With, say, Pfizer or Moderna or (less good but still probably enough) AstraZeneca. The same may be true for others but my ignorance about them is greater.
You need a model of the world that’s less black-and-white than “X works” versus “X doesn’tt work”. Any given intervention reduces transmission by a certain amount. Depending on how transmissible the currently-relevant strain of the virus is, different combinations of interventions will be sufficient or not. Collapsing all that to “works” versus “doesn’t work” is a bad idea; it makes it harder to think clearly.
At this point in the pandemic, the level of protection offered by masks is so uncertain (10% 1%? 0.1%?) and likely to be so small that masks are little more than a Hail Mary for those that don’t have access to vaccines, respirators, or PAPRs. While a Hail Mary doesn’t technically mean that it “doesn’t work,” it’s pretty close, and making a big deal about these distinctions is becoming a little pedantic.
For the vaccinated, recommending masks (which may or may not offer a tiny extra bit of protection) over vastly more effective respirators due to a small-to-none hassle factor seems a bit silly. It’s much more reasonable to recommend respirators or nothing.
You said something about “pure speculation” earlier, but I think that’s what you’re engaging in here.
What makes you think that masks offer “10%? 1%? 0.1%?” protection? Indeed, what do you mean by those numbers? What actual model of transmission leads you to think this?
[EDITED to add:] Actually, maybe I misunderstood you; is the “10%? 1%? 0.1%?” meant to be an amount of protection (in which case, why also say “and likely to be so small that …”—aren’t you saying the same thing twice?) or a probability of any protection at all (in which case, what are you smoking?)? Again, what actual model of transmission is this based on?
What masks do is to reduce the fraction (viruses breathed in) / (viruses breathed out), by blocking the passage of droplets or changing the pattern of air flow. Unless the later strains have evolved teleportation or something, it seems unlikely that the factor by which this fraction has reduced in any given situation is much different now from before. I’ve had trouble finding really convincing figures, but it seems like the typical factor for a surgical mask is somewhere on the order of a 3x-10x reduction in the “outward” direction, larger when speaking or coughing than when just breathing normally (which is good, because speaking and coughing make you emit a lot more viruses if infected). “Inward” protection seems to be somewhat less—maybe 2x? Home-made cloth masks appear to be substantially inferior to (ordinary, cheap) surgical masks.
This would mean e.g. that the amount of time you need to spend near an infected person in order to get infected yourself is 3-10x greater if they’re masked, 6-20x greater if you both are.
If you think that somehow none of this works any more because of the newer more infectious strains, or that it’s all nonsense and actually masks never had any substantial effect at all, then you should either give credible evidence that it doesn’t or explain a plausible way in which it would have stopped working (or would never have worked). “There was a wave of infections and masks didn’t stop it” is not credible evidence; that just means that the virus was infectious enough that whatever masks did wasn’t enough, which is perfectly consistent with masks doing a lot.
We know that masks have poor performance, because while masks seem to have eliminated the flu and to have stopped or significantly slowed down the spread of the original variants, especially in Asia, masks failed to have the same effect on the newer variants which caused the fall/winter wave. And since Delta is even more contagious than those variants, masks will be even less effective than they were during the last wave. How you can claim that this is not evidence is beyond me.
I also doubt that it’s useful or even possible to accurately calculate the efficacy of masks for the latest variants without doing lab work. How would you quantify the decrease in efficacy caused by increased infectivity due to better binding of the variants to human cells? How much more virus particles do these variants produce, if any, and how does that relate to mask efficacy? Is mask efficacy a spectrum or are there thresholds that suddenly render masks 0% effective in most or many situations? But since we already know that masks offer poor performance anyway, quantify exactly how poor the performance is (10%, 1%, 0.1%, or whatever) doesn’t seem to be all that important.
Masks have become a dangerous distraction from far more effective interventions.
You still seem to be assuming that “poor performance” = “not on their own sufficient to stop the latest variants growing exponentially”, and that is just unambiguously wrong.
Do you, or do you not, have any information that isn’t broadly consistent with the following crude model? 1. An infected person emits virus particles at some (somewhat random) rate, more when speaking or coughing than when breathing normally. 2. If you breathe in virus particles, there is some probability that you get infected; the probability is higher when the number of virus particles is higher. 3. If the infected person is wearing a mask, then the rate at which they emit virus particles is reduced by a constant factor somewhere in the vicinity of 5x. 4. If the not-yet-infected person is wearing a mask, then the number of virus particles reaching them is reduced by a constant factor somewhere in the vicinity of 2x. 5. Newer variants are more infectious, meaning some combination of (a) infected people emit more virus particles, or (b) the probability of infection for a given intake of virus particles is higher.
If this model is somewhere near the truth, then the only way for masks to be near-useless (“10%, 1%, 0.1%”, as you put it—but I asked you to explain what these numbers are supposed to mean and you didn’t, and I would still like you to) is if the newer variants cause such a colossal increase in the number of virus particles put out by an infected person, or in how effectively infectious they are, that being near them even briefly basically guarantees getting infected. Because otherwise, if you and they both wear masks then that means something like a 10x increase in how much exposure you can have before getting infected, and if the unmasked figure would be (say) 2 minutes’ conversation at a 2m distance, then that would turn into 20 minutes, and I at least have plenty of conversations that are longer than 2 minutes but shorter than 20 minutes.
Do you have good reason to believe that that model is far from the truth?
If not, do you have good reason to believe that the new variants are basically infinitely infectious?
If not, is there some other reason why the argument above fails?
Or have you just determined to keep saying “masks are useless” over and over, without ever making your claims precise enough to be evaluated, and without any actual model of how infection happens by which to justify your claim?
Once again, I appreciate that you are arguing for using something more effective than masks. I agree that things more effective than masks are more effective than masks. But it seems to me that you are either making almost certainly false claims about the effectiveness of masks (if you are saying that they aren’t what-I-call-effective, that they don’t substantially extend the range of what one can do without substantial risk of infection) or else using very misleading language to make the claims you are (if you are only saying that they are not sufficient on their own to stop a wave of Delta-variant COVID-19 -- which I agree is almost certainly the case), and I wish you wouldn’t do either of those things.
Given the fact that we already know that masks have poor performance based on the what I’ve already mentioned, models are pointless for most situations.
If you’re referring to modelling a strategy of maximizing personal (rather than public) protection with a poor performing tool, models could help you do that, but in the case of masks, it will turn out that most strategies are impractical because 1) there will be too many variables to keep track of, 2) some variables will be impossible or hard to obtain, and 3) some variables will be hard to control even with perfect knowledge. With or without a mask, if the distance between people is far enough, infection will be avoided regardless of infectivity due to dilution. If the distance is between two people, you may be able to calculate a minimum safe distance if you know all of the variables. Some of these variables are room size, ventilation, infectivity, mask type, rates of breathing and vocalization, and vaccination status. You’d also need to know if the room was previously occupied and by whom. Some of these these variables will be known but some will not be. You’ll also need to recompute these variables once they change. If you’re dealing with a simple model with two people in which nothing changes, this strategy might work. But real world cases are almost nothing like this. What if you go to another room or another person walks in? Is the ventilation the same? Is the person vaccinated? What kind of mask are they wearing? How many people were in the room before you walked in (aerosols can become suspended for hours even if the people that generated them are no longer around)? Modeling this stuff quickly becomes impractical, and if you can avoid that by wearing a respirator, why bother?
“10%, 1%, 0.1%” was meant to poke fun at the attempt of precisely quantifying the poor performance of masks and is not based on any data.
I don’t think further discussion in this thread is likely to prove fruitful.
Thanks! I’m not particularly worried about outdoor things (though your comments on crowds help fill in a gap where I had some uncertainty). More curious whether to attend indoor events without a vaccination restriction.