I kinda gave up on being totally up to date on COVID stuff but here my assessment on masks and mask mandates:
1. The use of masks correlates with better pandemic control. At this point it's both supported by:
- physics experiments (barrier testing showing reduced droplet travel and count),
- biochemical studies showing reduced viral particles below in vitro infectability,
- biological studies (in lab animals mask-like barriers reduced transmissions),
- retrospective medical studies (from the SARS-1 pandemic),
- prospective data from hospital workers and self-reported adherence data from large (>100K) surveys.
That's almost all the levels of evidence you need. A study like DANMASK-19 could have completed the picture, but (besides the noob errors) such study is very hard to ethically execute (meaning, on a larger scale you can't use a control group where you tell people not to wear masks, when the above evidence is already piling and suggesting that you'd hurt the people in the control arm).
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2. The pandemic and policy interventions should be evaluated in waves, so it's generally not black and white.
- There is a consensus that the global pandemic response was abysmal even before the 1st wave hit and I think it was mainly luck for some countries like Czechia to avoid it.
- The second wave was avoidable as seen per the EU data vs. the USA. This is where policy did make a difference. Mask mandates (could have) played a crucial role here:
(Note that the counties with the mask mandates were the highest populated, so if we compared matching groups with matched population density, the differences would have been even more striking.)
www.ncbi.nlm.nih.gov
- The third wave was again somewhat inevitable (it's a seasonal virus after all), but again could have been mitigated.
- For the 4th wave it again became a policy/implementation game. Countries on top of vaccinations averted it. You can look at the EU vs. the USA here. This is also the first time in the pandemic where we did quite well!
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3. Now if you look at the policies on masking, you can also see that in the newest studies mask mandates lost their impact, but adherence to masking DID NOT. By now, a 10% increase in self-reported mask adherence was associated with a 3.5x higher (!!!) likelihood of pandemic control, yet mask mandates did not reach a statistical significance in increasing self-reported mask adherence.
To translate this, Rand Paul and ilk would try to spin this as "mask mandates don't work". In reality, it's more like
"mask mandates don't motivate people to wear masks [good leadership does]". Part of it is being influencers (I count politicians here) telling people that masks don't work do significant damage.
Face masks have become commonplace across the USA because of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) epidemic. Although evide…
www.sciencedirect.com
www.cbsnews.com
, but it's still a good measure to spot noobs). 
