Preface: My employer requires vaccination of all staff and students; also, we're totally gonna have a nice-sized outbreak by.... October, maybe. I think they should make everyone wear a mask from day one, but it's not gonna happen.
The CDC recently had a nice private slideshow (which the WaPo immediately acquired) with all kinds of 'Oh, !@#$%' data about our favorite latest variant. Behold, my favorite 'enjoy the next six months' slide:
Note particularly their model assumptions about masking. These are likely to be lower-bound estimates of effectiveness. (Also, 'how much aerosol did I inhale' and 'will I get sick' are not the same question. How many exposures does it take to get sick? It depends....) How can we figure out average effectiveness? Someone did a great study some time ago! (Briefly, they used soft mannequins and radiation to measure particle reception.)
Figure 4: Exposure data for tidal breathing, expressed as a percent of aerosol exhaled with a two-sided 95% CI, plotted for different masks on the Source or Receiver. An asterisk (*) denotes significance for a p-value <0.05 using the Kruskal-Wallis one-way analysis of variance. S = Source, R = Receiver, MaxEx = Maximum Exposure, SMnat = natural fit surgical mask, SF = SecureFit Ultra fitted surgical mask, N95 = 3M N95 respirator, N95vas = 3M N95 respirator with a Vaseline seal.
Figure 5: Exposure data for cough, expressed as a percent of aerosol exhaled with a two-sided 95% CI, plotted for different masks on the Source or Receiver. An asterisk (*) denotes significance for a p-value <0.05 using the Kruskal-Wallis one-way analysis of variance. S = Source, R = Receiver, MaxEx = Maximum Exposure, SMnat = natural fit surgical mask, SF = SecureFit Ultra fitted surgical mask, N95 = 3M N95 respirator, N95vas = 3M N95 respirator with a Vaseline seal.
So, in summary, if you can convince your local administration/ school board/ city council to re-institute indoor masking, that would be great, because it is (according to this one very well-conducted study) 25 times more effective at reducing respiratory droplets as just 'people who want to' wearing a mask.
Cold City county just re-instituted indoor masking for everyone. There's a good chance my kids will be masked in school this year. Bicycle Company already has 97% vaccination rate, but is now requiring vaccination as a condition of employment. So things in my corner of Cold State are going ok.
ReplyDeleteCould be worse! Predictably the Other College didn't require it for staff so that's gonna... go great too.
Delete