Back in January or so, Bavaria at least mandated FFP2 (roughly equivalent to US N95) masks be worn in shops, buses and presumably similar environments. At least Berlin followed suit some months later with a similar measure.
Is there any epidemiological study that tries to isolate the effects of this specific measure (relative to mask mandates in general, using just surgical masks)?
I've done a bit of searching, all I can find are more news stories on the FFP2 mandating... but noting much on whether it had any specific effects.
I'm asking about this because the different times when masks (of any kind) were mandated in various parts Germany [earlier in the pandemic] was used as a way to set-up a comparison in a fairly cited study on mask-mandates effectiveness. So, I was hoping something similar could have been done for the effects of [mandating] FFP2/N95 in the general population (well, at least in those settings that they were mandated for).