OK. Seriously, what is the latest on masks? Bottom line: if most people wear an effective mask we can significantly curb viral transmission
It is increasingly clear that there are differences in mask quality and protection. Here is one example of a recent report:
3-layer surgical mask (1)
Cotton-polypropylene-cotton mask (5)
2-layer polypropylene apron mask (4)
2-layer cotton, pleated style mask (13)
2-layer cotton, pleated style mask (7)
Valved N95 mask (2)
2-layer cotton, Olson style mask (8)
1-layer Maxima AT mask (6)
1-layer cotton, pleated style mask (10)
2-layer cotton, pleated style mask (9)
Knitted mask (3) NOT GOOD
Double-layer bandana (12) NOT GOOD
Gaiter-style neck fleece (11) USELESS
Read a more in depth study here: https://www.nature.com/articles/s41598-020-72798-7#Fig4
Another set of data looks at transmission among airline passengers on Emirates and specifically on their 8h flights Dubai – Hongkong. Emirates has a strictly enforced mask policy. Even on completely booked flights with, for example, 7 COVID+ passengers, there was no transmission to other passengers! https://www.npr.org/sections/goatsandsoda/2020/10/20/925892185/do-masks-really-cut-your-risk-of-catching-covid-19-on-long-plane-flights
Their conclusion is that strictly enforced mask usage works.
The bottom line: if most people wear masks we can significantly curb viral transmission. It is useful to have an effective mask too.
The following graph plots adherence to mask policy versus quality of the mask used. With poor quality masks it does not matter whether a high percent of people use a mask. And with poor adherence to mask wearing rules, even those that wear a high quality mask are not protected. One needs both a good mask and strict mask use enforcement.
Good report. Thanks David.