Re:MIT study finds indoor mask wearing much more effective t...
by woofie11 on Thursday April 29, 2021 @09:11AM
(#26980701)
What we know is that:
* Cloth masks reduce viral loads by somewhere around 30-70%.
* High-quality masks reduce them by e.g. 70-95% depending on how they're fitted.
* We know risk of infection (and severity) is related to viral load, but we don't quite know how.
* We have a lot of well-documented evidence from Asia about reduced infections when high-quality masks are used consistently (e.g. buses in China, hospitals in Singapore, etc.).
* We know masks significantly reduce R0, but we don't know by how much; error bars are huge, and dependent on a slew of other variables.
The key difference between public health settings and hospital settings is opportunities to be infected. As a doctor, I might have 10 opportunities per day, and if I don't have properly-fitted PPE one of those times, and I'm susceptible, I'll catch COVID19. This means half-measures do very little.
In a public health setting, it's a numbers game:
* Personal: If I have 1 opportunity per 2 weeks to be infected, and I reduce odds by 50%, I'm half as likely to catch COVID personally.
* Public health: If I reduce infection odds by 50%, R0 is cut in half. That's huge. Our exponent is very different.
So cloth masks are definitely worth the $2, but won't stop you from catching COVID if you take other risks. If everyone wore N95 or even surgical or nanofiber masks, COVID would probably be gone pretty quickly.
* Cloth masks reduce viral loads by somewhere around 30-70%.
* High-quality masks reduce them by e.g. 70-95% depending on how they're fitted.
* We know risk of infection (and severity) is related to viral load, but we don't quite know how.
* We have a lot of well-documented evidence from Asia about reduced infections when high-quality masks are used consistently (e.g. buses in China, hospitals in Singapore, etc.).
* We know masks significantly reduce R0, but we don't know by how much; error bars are huge, and dependent on a slew of other variables.
The key difference between public health settings and hospital settings is opportunities to be infected. As a doctor, I might have 10 opportunities per day, and if I don't have properly-fitted PPE one of those times, and I'm susceptible, I'll catch COVID19. This means half-measures do very little.
In a public health setting, it's a numbers game:
* Personal: If I have 1 opportunity per 2 weeks to be infected, and I reduce odds by 50%, I'm half as likely to catch COVID personally.
* Public health: If I reduce infection odds by 50%, R0 is cut in half. That's huge. Our exponent is very different.
So cloth masks are definitely worth the $2, but won't stop you from catching COVID if you take other risks. If everyone wore N95 or even surgical or nanofiber masks, COVID would probably be gone pretty quickly.