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One result of the research bonanza is discovering just how effective masks are. Research is pouring out showing that N95 mask effectiveness exceeds all expectat

One result of the research bonanza is discovering just how effective masks are. Research is pouring out showing that N95 mask effectiveness exceeds all expectations. It used to be assumed that N95, especially unfitted, had an effectiveness between 0-50%. And that surfaces play a large role in transmissions. It's increasingly obvious that neither are true. Hell, the CDC came out and said the epidemic might be over after 4-6 weeks of universal mask usage. And that masks may be more effective than the vaccine. Thats hyuge, and shows just how idiotic certain people in the US government were with initial guidance on masks.

tharne 6y ago
Why on earth are people downvoting this? The fact that universal use of even basic cloth masks dramatically reduces the spread of COVID is nothing short of a miracle.
- throwaway189262 6y ago
  Probably brigaded by bots of some kind
- parliament32 6y ago
  WHO disagrees with you: https://www.who.int/emergencies/diseases/novel-coronavirus-2019/question-and-answers-hub/q-a-detail/q-a-on-covid-19-and-masks https://www.who.int/emergencies/diseases/novel-coronavirus-2... >Non-medical, fabric masks are being used by many people in public areas, but there has been limited evidence on their effectiveness and WHO does not recommend their widespread use among the public for control of COVID-19. Further reading: https://www.who.int/publications/i/item/advice-on-the-use-of-masks-in-the-community-during-home-care-and-in-healthcare-settings-in-the-context-of-the-novel-coronavirus-(2019-ncov)-outbreak https://www.who.int/publications/i/item/advice-on-the-use-of... >Many countries have recommended the use of fabric masks/face coverings for the general public. At the present time, the widespread use of masks by healthy people in the community setting is not yet supported by high quality or direct scientific evidence and there are potential benefits and harms to consider >Results from cluster randomized controlled trials on the use of masks among young adults living in university residences in the United States of America indicate that face masks may reduce the rate of influenza-like illness, but showed no impact on risk of laboratory-confirmed influenza.(62, 63) At present, there is no direct evidence (from studies on COVID- 19 and in healthy people in the community) on the effectiveness of universal masking of healthy people in the community to prevent infection with respiratory viruses, including COVID-19. The whole PDF is worth a read, especially the "Guidance on the use of masks for the general public", and is the most recent guidance from WHO about mask use.
  - phobosanomaly 6y ago
    You didn't include the sentence right after the one you quoted from that first link: "However, for areas of widespread transmission, with limited capacity for implementing control measures and especially in settings where physical distancing of at least 1 metre is not possible – such as on public transport, in shops or in other confined or crowded environments – WHO advises governments to encourage the general public to use non-medical fabric masks." Sounds to me like although they don't have 100% gold-standard RCT evidence to say that cloth masks reduce transmission by this %, they still see it as the single best method to prevent spread of the virus under 'real-world' conditions.
    - parliament32 6y ago
      They're talking around "it doesn't do much of anything, but wear them if it makes you feel better". Medical masks absolutely work, but the cloth ones really don't. See page 9 of the linked PDF for filtration efficiency of various materials... Your best bet is something made of cotton and the thickness of a sweater, which rings in at 26% (contrast to N95 masks at 95%) -- and keep in mind this is only the initial filtration efficiency, it starts dropping as soon as you breathe a few times and get it damp. >single best method On the contrary, it's literally the worst out of all the measures they recommend, like physical distancing and hand washing.
      - phobosanomaly 6y ago
        Iono, from page 6: "However, taking into account the available studies evaluating pre- and asymptomatic transmission, a growing compendium of observational evidence on the use of masks by the general public in several countries, individual values and preferences, as well as the difficulty of physical distancing in many contexts, WHO has updated its guidance to advise that to prevent COVID-19 transmission effectively in areas of community transmission, governments should encourage the general public to wear masks in specific situations and settings as part of a comprehensive approach to suppress SARS-CoV-2 transmission (Table 2)." The later stuff is on filtration by cloth masks. I don't think that's why cloth masks are effective. They're terrible filters. Don't think of cloth masks as filters. N95 does that, but cloth masks are useless for that. What they do is alter the trajectory of respiratory droplets coming out of your mouth. When you talk, your vocal cords vibrate, and that aerosolizes tiny liquid droplets from your respiratory tract. These droplets may contain viral particles. When you wear a cloth mask, you're not filtering out those particles, you're altering their trajectory. With the cloth barrier, the droplets catch on the mask, or are deflected at an angle that is not straight-ahead at the level of other people's mouth. So if everyone is wearing masks, then it disrupts the vectors of virus-containing droplets being directed from one person's mouth directly into another person's airway, especially during vocalization. The redirected particles spent more time in the air, and so have more of a chance to dry out before being inhaled. It's one-big harm-reduction strategy, where the goal is not to completely filter out viral particles, but rather to make sure that you're not directly inhaling too many on a given exposure (sub-infectious dose). That's how I think of it. There's no RCT or anything that proves it, but I haven't thought of any good argument for why this isn't a good model for what's going on. Although hand-washing and physical distance are the gold-standard, part of the problem is that it doesn't seem to be feasible as an option (at least in the US), so we need to rely more heavily on the single best harm-reduction strategy, which seems to be masks at the moment. It's the difference between the best option in a lab, and the best option in a crowded grocery store or subway train where people aren't necessarily going to follow the rules.

tharne 6y ago

Why on earth are people downvoting this? The fact that universal use of even basic cloth masks dramatically reduces the spread of COVID is nothing short of a miracle.

throwaway189262 6y ago
Probably brigaded by bots of some kind
parliament32 6y ago
WHO disagrees with you: https://www.who.int/emergencies/diseases/novel-coronavirus-2019/question-and-answers-hub/q-a-detail/q-a-on-covid-19-and-masks https://www.who.int/emergencies/diseases/novel-coronavirus-2... >Non-medical, fabric masks are being used by many people in public areas, but there has been limited evidence on their effectiveness and WHO does not recommend their widespread use among the public for control of COVID-19. Further reading: https://www.who.int/publications/i/item/advice-on-the-use-of-masks-in-the-community-during-home-care-and-in-healthcare-settings-in-the-context-of-the-novel-coronavirus-(2019-ncov)-outbreak https://www.who.int/publications/i/item/advice-on-the-use-of... >Many countries have recommended the use of fabric masks/face coverings for the general public. At the present time, the widespread use of masks by healthy people in the community setting is not yet supported by high quality or direct scientific evidence and there are potential benefits and harms to consider >Results from cluster randomized controlled trials on the use of masks among young adults living in university residences in the United States of America indicate that face masks may reduce the rate of influenza-like illness, but showed no impact on risk of laboratory-confirmed influenza.(62, 63) At present, there is no direct evidence (from studies on COVID- 19 and in healthy people in the community) on the effectiveness of universal masking of healthy people in the community to prevent infection with respiratory viruses, including COVID-19. The whole PDF is worth a read, especially the "Guidance on the use of masks for the general public", and is the most recent guidance from WHO about mask use.
- phobosanomaly 6y ago
  You didn't include the sentence right after the one you quoted from that first link: "However, for areas of widespread transmission, with limited capacity for implementing control measures and especially in settings where physical distancing of at least 1 metre is not possible – such as on public transport, in shops or in other confined or crowded environments – WHO advises governments to encourage the general public to use non-medical fabric masks." Sounds to me like although they don't have 100% gold-standard RCT evidence to say that cloth masks reduce transmission by this %, they still see it as the single best method to prevent spread of the virus under 'real-world' conditions.
  - parliament32 6y ago
    They're talking around "it doesn't do much of anything, but wear them if it makes you feel better". Medical masks absolutely work, but the cloth ones really don't. See page 9 of the linked PDF for filtration efficiency of various materials... Your best bet is something made of cotton and the thickness of a sweater, which rings in at 26% (contrast to N95 masks at 95%) -- and keep in mind this is only the initial filtration efficiency, it starts dropping as soon as you breathe a few times and get it damp. >single best method On the contrary, it's literally the worst out of all the measures they recommend, like physical distancing and hand washing.
    - phobosanomaly 6y ago
      Iono, from page 6: "However, taking into account the available studies evaluating pre- and asymptomatic transmission, a growing compendium of observational evidence on the use of masks by the general public in several countries, individual values and preferences, as well as the difficulty of physical distancing in many contexts, WHO has updated its guidance to advise that to prevent COVID-19 transmission effectively in areas of community transmission, governments should encourage the general public to wear masks in specific situations and settings as part of a comprehensive approach to suppress SARS-CoV-2 transmission (Table 2)." The later stuff is on filtration by cloth masks. I don't think that's why cloth masks are effective. They're terrible filters. Don't think of cloth masks as filters. N95 does that, but cloth masks are useless for that. What they do is alter the trajectory of respiratory droplets coming out of your mouth. When you talk, your vocal cords vibrate, and that aerosolizes tiny liquid droplets from your respiratory tract. These droplets may contain viral particles. When you wear a cloth mask, you're not filtering out those particles, you're altering their trajectory. With the cloth barrier, the droplets catch on the mask, or are deflected at an angle that is not straight-ahead at the level of other people's mouth. So if everyone is wearing masks, then it disrupts the vectors of virus-containing droplets being directed from one person's mouth directly into another person's airway, especially during vocalization. The redirected particles spent more time in the air, and so have more of a chance to dry out before being inhaled. It's one-big harm-reduction strategy, where the goal is not to completely filter out viral particles, but rather to make sure that you're not directly inhaling too many on a given exposure (sub-infectious dose). That's how I think of it. There's no RCT or anything that proves it, but I haven't thought of any good argument for why this isn't a good model for what's going on. Although hand-washing and physical distance are the gold-standard, part of the problem is that it doesn't seem to be feasible as an option (at least in the US), so we need to rely more heavily on the single best harm-reduction strategy, which seems to be masks at the moment. It's the difference between the best option in a lab, and the best option in a crowded grocery store or subway train where people aren't necessarily going to follow the rules.