3 ms·

First, as the sibling comment pointed out, the Cochrane review article didn't show that masks were ineffective. "Relatively low numbers of people followed the g

First, as the sibling comment pointed out, the Cochrane review article didn't show that masks were ineffective. "Relatively low numbers of people followed the guidance about wearing masks or about hand hygiene, which may have affected the results of the studies" [1]. Their results were inconclusive since the people the asks to wear masks, didn't. But there's still evidence that masks are effective. The question of whether N95 filter media can block virus-carrying droplets is a _physics_ question-- which has been replicated in experiment after experiment since the 90s ([2] is a recent study). I've done a lot of looking, but I've yet to find any explanation as to why if someone is wearing a (properly fitted) N95, so their air goes through a filter media, which has been repeatedly shown to block droplets, they could still inhale disease-carrying droplets. [1]: https://www.cochrane.org/news/featured-review-physical-interventions-interrupt-or-reduce-spread-respiratory-viruses https://www.cochrane.org/news/featured-review-physical-inter... [2]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9947910/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9947910/

autoexec 3y ago
> I've yet to find any explanation as to why if someone is wearing a (properly fitted) N95, so their air goes through a filter media, which has been repeatedly shown to block droplets, they could still inhale disease-carrying droplets. It's worth keeping in mind that even if someone wearing an N95 mask does manage to inhale some percentage of the airborne disease-carrying droplets around them, viral load matters a lot. A tiny amount of virus could be fought off by the immune system before it has a chance to take hold in the body, and even if that fails and the virus does infect the body, larger exposures tend to result in worse outcomes. Even an imperfect protection can have a beneficial effect. It's the same for people spreading the virus. Even if a mask isn't perfect, that doesn't make it useless. Putting just about anything in front of someone's virus spewing face holes is going to reduce the amount of virus that gets into the air and limit how far it spreads. This is why we teach small children to "vampire cough". Not because the inside of our elbows provide N95 levels of protection, but because doing so still helps to prevent the spread of disease.
gadders 3y ago
>>Their results were inconclusive since the people the asks to wear masks, didn't. Their review was at the macro, population level. If people aren't wearing masks properly through carelessness or ignorance, this proves their point. Shooting a virus at a masked mannequin in a lab might show some prevention, but in the real world people forget and scratch their nose, rub their eyes, get sneezed on by a stranger etc.
- 1224530282 3y ago
  I agree that the Cochrane review is better evidence of "if you don't wear/use a mask properly, it won't work," rather than "masks don't work." (This is one of the reasons I'm against mask mandates, btw.) I'm invested in this only because, due to my health condition, I don't want to get covid. As far as I'm aware, the evidence says that so long as I properly wear an N95 (so I'm not taking my mask off to scratch my nose, have passed a fit test, etc.), I will significantly reduce my risk of getting covid.
  - gadders 3y ago
    But rather than "if you don't wear/use a mask properly, it won't work", I'd more restate it as "for a given population size, enough people would mess up that making everyone wear one would not slow the spread of the disease". I also think that if you, as an individual, are especially diligent it may well lower your personal chances of catching COVID. And given your health conditions, I really hope that is the case for you. But I think we are broadly in agreement.
    - jMyles 3y ago
      > I'd more restate it as "for a given population size, enough people would mess up that making everyone wear one would not slow the spread of the disease". ...but this is even less conservative than the review summary, which was inexplicably panned. The clause "enough people would mess up that making everyone wear one would not slow the spread of the disease" is part of the consideration that goes into "community transmission" (or the phrase "in the community", which is sometimes used in formal publications as an abstraction for real-world compliance levels) and is distinct from "individual transmission". The sentence in question is: "Wearing masks in the community probably makes little or no difference to the outcome of influenza-like illness (ILI)/COVID-19 like illness compared to not wearing masks (risk ratio (RR) 0.95, 95% confidence interval (CI) 0.84 to 1.09; 9 trials, 276,917 participants;" [0] ...it's hard to imagine how this extremely sober (and factually proper) extrapolation of the data has caused such a kerfuffle. Is it any wonder that the people who have been studying this topic since before it was cool are puzzled? 0: https://pubmed.ncbi.nlm.nih.gov/36715243/ https://pubmed.ncbi.nlm.nih.gov/36715243/ edit: my apologies - I just read that you addressed this elsewhere in the thread. It seems that we are in agreement (and I just don't think there is a reasonable alternative assessment for any numerate / literate reading of the data.)

autoexec 3y ago

> I've yet to find any explanation as to why if someone is wearing a (properly fitted) N95, so their air goes through a filter media, which has been repeatedly shown to block droplets, they could still inhale disease-carrying droplets. It's worth keeping in mind that even if someone wearing an N95 mask does manage to inhale some percentage of the airborne disease-carrying droplets around them, viral load matters a lot. A tiny amount of virus could be fought off by the immune system before it has a chance to take hold in the body, and even if that fails and the virus does infect the body, larger exposures tend to result in worse outcomes. Even an imperfect protection can have a beneficial effect. It's the same for people spreading the virus. Even if a mask isn't perfect, that doesn't make it useless. Putting just about anything in front of someone's virus spewing face holes is going to reduce the amount of virus that gets into the air and limit how far it spreads. This is why we teach small children to "vampire cough". Not because the inside of our elbows provide N95 levels of protection, but because doing so still helps to prevent the spread of disease.

gadders 3y ago

>>Their results were inconclusive since the people the asks to wear masks, didn't. Their review was at the macro, population level. If people aren't wearing masks properly through carelessness or ignorance, this proves their point. Shooting a virus at a masked mannequin in a lab might show some prevention, but in the real world people forget and scratch their nose, rub their eyes, get sneezed on by a stranger etc.

1224530282 3y ago
I agree that the Cochrane review is better evidence of "if you don't wear/use a mask properly, it won't work," rather than "masks don't work." (This is one of the reasons I'm against mask mandates, btw.) I'm invested in this only because, due to my health condition, I don't want to get covid. As far as I'm aware, the evidence says that so long as I properly wear an N95 (so I'm not taking my mask off to scratch my nose, have passed a fit test, etc.), I will significantly reduce my risk of getting covid.
- gadders 3y ago
  But rather than "if you don't wear/use a mask properly, it won't work", I'd more restate it as "for a given population size, enough people would mess up that making everyone wear one would not slow the spread of the disease". I also think that if you, as an individual, are especially diligent it may well lower your personal chances of catching COVID. And given your health conditions, I really hope that is the case for you. But I think we are broadly in agreement.
  - jMyles 3y ago
    > I'd more restate it as "for a given population size, enough people would mess up that making everyone wear one would not slow the spread of the disease". ...but this is even less conservative than the review summary, which was inexplicably panned. The clause "enough people would mess up that making everyone wear one would not slow the spread of the disease" is part of the consideration that goes into "community transmission" (or the phrase "in the community", which is sometimes used in formal publications as an abstraction for real-world compliance levels) and is distinct from "individual transmission". The sentence in question is: "Wearing masks in the community probably makes little or no difference to the outcome of influenza-like illness (ILI)/COVID-19 like illness compared to not wearing masks (risk ratio (RR) 0.95, 95% confidence interval (CI) 0.84 to 1.09; 9 trials, 276,917 participants;" [0] ...it's hard to imagine how this extremely sober (and factually proper) extrapolation of the data has caused such a kerfuffle. Is it any wonder that the people who have been studying this topic since before it was cool are puzzled? 0: https://pubmed.ncbi.nlm.nih.gov/36715243/ https://pubmed.ncbi.nlm.nih.gov/36715243/ edit: my apologies - I just read that you addressed this elsewhere in the thread. It seems that we are in agreement (and I just don't think there is a reasonable alternative assessment for any numerate / literate reading of the data.)