I don't have much, but maybe this contains a hint on the effects of mask usage on the German death growthrate. https://www.facebook.com/photo.php?fbid=10157238440973015 (Masks about 25.4 - the effect should be visible around the middle of May)

After looking closely I found a small move into the wrong direction (maybe caused by something else?!??)

This is a pretty nice and very recent summary: https://science.sciencemag.org/content/early/2020/06/02/scie...

There have been studies which have found that the virus can aerosolize, but it hasn't been established that infectious spread occurs this way. For example, it could be that viral concentrations in an aerosolized form aren't enough to cause an infection (or maybe they can get there, in prolonged close quarters, but by then you're being exposed multiple ways, so it doesn't matter or can't be determined). Either way it seems that the protocol for preventing transmission probably won't change much; the current protocols (including ubiquitous mask usage) have been enough for Korea, Taiwan etc. to control the spread.

It cannot be established without exposing healthy people to the virus, so it must be assumed.

I think it can change something: currently masks are seen as a necessary evil in stores and public transport. They could and should become ubiquitous.

As far as I have seen, currently people don't use masks for close contact talking situations (family, friends, work, chatting...).

With mask usage in Germany I see only negative trends in the growthrate of both case and death. I think to make them work something has to be changed.

There is a good chance that it now only works as a reverse placebo - it makes people feel confident and pushes them into more risky behaviour - most likely net negative.

Jena's claiming that they made a difference for them. We'll see what happens in Berlin and Munich after the protests...