4 ms·

One note here is that "aerosol" =/= "spread through the air". The debate was not over whether or not the virus was spread through the air, but whether or not it

by Fomite 6y ago

One note here is that "aerosol" =/= "spread through the air". The debate was not over whether or not the virus was spread through the air, but whether or not it was spread via droplets (relatively "large" particles that spread through the air, but will settle relatively quickly onto surfaces) or aerosols (relatively small particles that are likely to linger for longer). The evidence for aerosol transmission outside of specific medical procedures (the aptly named "aerosol generating procedures") wasn't nearly as overwhelming, and most epidemiologists I know were more than willing to characterize the transmission of COVID-19 as likely being on a continuum (documents I wrote were discussing this in early May).

taurath 6y ago
That’s a good distinction, but I’m not sure how that jives with telling the public not to wear masks, if they knew it was airborne.
- Fomite 6y ago
  Essentially, early in the epidemic, that was fueled by two things: 1) Previous studies for flu have shown that masks have very little effect. 2) There was concern about fomite transmission, and for good reason - both from previous coronavirus outbreaks (SARS and MERS) and because of the initial settings (hospitals and the cruise ship). Donning and doffing contaminated PPE is a skill, and an actually fairly difficult one. The combination of the two led to the active concern that the reduction in transmission due to mask wearing might very well be offset by people self-inoculating via their mouth or eyes. The shift in thinking came about via two mechanisms as well: 1) The fomite transmission thing appeared to be less of a big deal than initial studies indicated. 2) Previous studies had looked at protecting people by wearing masks. The newer paradigm for masks is primarily focused on reducing the amount of virus asymptomatic or mildly symptomatic individuals are putting into the environment via droplets or aerosols. Hence things like "My mask protects you, your mask protects me."
  - taurath 6y ago
    For point 1 above and point 2 below: to my knowledge this was widely already known by the medical community, and is widely used throughout asia to protect others against any cough or airborne diseases. Did the previous studies for flu only take into consideration the protecting value for the individual wearing it? How does the wearing of masks during the spanish flu fit into that? Was that not effective then? I guess its hard to say. It seems, well, obvious in hindsight surely, but you'd think that something this obvious in hindsight would be figured out by experts beforehand. Telling people actively to not wear masks seems like they not only missed the shot but were actively harmful.

by Fomite 6y ago

taurath 6y ago

That’s a good distinction, but I’m not sure how that jives with telling the public not to wear masks, if they knew it was airborne.

Fomite 6y ago
Essentially, early in the epidemic, that was fueled by two things: 1) Previous studies for flu have shown that masks have very little effect. 2) There was concern about fomite transmission, and for good reason - both from previous coronavirus outbreaks (SARS and MERS) and because of the initial settings (hospitals and the cruise ship). Donning and doffing contaminated PPE is a skill, and an actually fairly difficult one. The combination of the two led to the active concern that the reduction in transmission due to mask wearing might very well be offset by people self-inoculating via their mouth or eyes. The shift in thinking came about via two mechanisms as well: 1) The fomite transmission thing appeared to be less of a big deal than initial studies indicated. 2) Previous studies had looked at protecting people by wearing masks. The newer paradigm for masks is primarily focused on reducing the amount of virus asymptomatic or mildly symptomatic individuals are putting into the environment via droplets or aerosols. Hence things like "My mask protects you, your mask protects me."
- taurath 6y ago
  For point 1 above and point 2 below: to my knowledge this was widely already known by the medical community, and is widely used throughout asia to protect others against any cough or airborne diseases. Did the previous studies for flu only take into consideration the protecting value for the individual wearing it? How does the wearing of masks during the spanish flu fit into that? Was that not effective then? I guess its hard to say. It seems, well, obvious in hindsight surely, but you'd think that something this obvious in hindsight would be figured out by experts beforehand. Telling people actively to not wear masks seems like they not only missed the shot but were actively harmful.