You did look at the pictures, right? People packed in like sardines - no masks.
You did read my reply, right?
Here is a recent study of mask mandates and usage: https://www.medrxiv....21257385v1.full
No correlation between mask and non-mask states when it comes COVID spread.
Yes, masks don't work so well for the more contagious variants that drove the fall/winter wave. This is obvious; you don't need any fancy studies to prove it.
But I'm more skeptical of this study's claims about the summer wave.
For the Summer wave, Northeast states were excluded because they deviated from other states with respect to covariation between normalized cases and growth. For the Fall-Winter wave, Hawaii was excluded because it deviated from other states with respect to covariation between normalized cases and growth. Infectious disease research commonly uses OLS [20, 21], with simple linear and simple ln-linear models reported in recent COVID-19 studies [22, 23]. We used ordinary least squares (OLS) for homoscedastic data and weighted least squares (WLS) for heteroscedastic data, as determined by the GraphPad Prism Test for Homoscedasticity. Regardless of statistical significance, R2 values denote coefficients of determination for lines of best fit with unconstrained slopes.
Is excluding the Northeast states valid? I don't have the expertise of a statistician, but it seems kind of suspicious.
Also, the summer wave happened mostly in the southern states which may have had less compliance regardless of mandates.
And another recent study (cited earlier in this thread) comes to the opposite conclusion when focusing on adherence, not just on mandates.
https://www.longecit...ndpost&p=905594
This is similar to the previous uncontrolled CDC study (cited earlier in this thread) which showed that mask usage barely made even a minor dent in the spread of COVID in the US.
This is also in line with previous pandemic studies (cited earlier in this thread) over the last 100 years or so. As a population-wide pandemic response, masks are not very effective.
Earlier in this thread we also discussed why those studies were of poor quality.
The bottom line for me hasn't changed: masks probably work for less contagious covid variants (spring wave, Asia versus the rest of the world) and respiratory viruses such as the 2020/2021's flu strains (which got wiped out) but don't work so well for the more contagious variants (the fall/winter wave).
Edited by Florin, 06 June 2021 - 02:32 AM.