We don't need orthodoxy, we need truth.

A month or so back a Danish team of researchers published a study which found statistically no effect to wear masks in terms of probability of being infected.  It was of course a spark to dry tender with so many institutions desperate to advance the idea that masks are a panacea and so many people ready to see masks as a mere pawn in partisan and political power struggles.

I have not commented on the study because I haven't had time to dig into the details and it was clear that much of the debate seemed to be researchers talking across one another rather finding agreement on parts of the study which might be reliable and which might be fallible.  I am glad I waited because Here's How to Think About the Danish Mask Study — What the DANMASK-19 trial showed and didn't show about mask use and COVID-19 by Vinay Prasad has done the leg work.  Thanks goodness for independent thinkers like him do the hard work to check the facts and focus on getting closer to the truth rather than the more popular approach of point scoring.

His description is balanced and clear. 

I start then with a humility as I take on the Danish Mask Study, published on Wednesday in the Annals of Internal Medicine. This is a 4,800-person randomized trial that took place in the spring and early summer in Denmark. The trial was run at a time where most Danes did not wear masks when they left their house. It told participants to practice social distancing and randomly assigned them with the advice to wear a mask (and even gave them 50 surgical masks), advising them to change it after every 8 hours of use, or gave them no advice to wear mask, and followed them to see how many acquired SARS-CoV-2 by PCR or antibody testing. The answer was a nearly identical proportion -- 42 of 2,393 people (1.8%) in the mask group and 53 of 2,470 (2.1%) in the no-mask group. The difference was not statistically significant.
 

[snip]

 The Danish trial shows that this specific mask recommendation (plus a box of masks) made during the SARS-CoV-2 pandemic, with background rates of 2% PCR acquisition, failed to show that mask wearing reduces risk by 50%. In places where there is modest SARS-CoV-2 transmission (like Denmark during these months), there is insufficient evidence to suggest wearing a mask as you go about daily errands will protect you from infection. That is good to know!

Indeed.  It doesn't answer the global and ambiguous questions about mask wearing.  It answers a very specific question about mask wearing under very specific conditions and provides a useful answer.

In that regard, it is not dissimilar to the Marine Corps study I posted about a couple of weeks ago, I don't know but I've been told; Covid-19's is just a cold . . . 

Two smallish studies well executed under pretty specified or controlled circumstances.  They both add to our knowledge and yet both are being treated as pariah findings because they are seen as weakening the orthodoxy.  We don't need orthodoxy, we need truth.