You can add location information to your Tweets, such as your city or precise location, from the web and via third-party applications. You always have the option to delete your Tweet location history. Learn more
By the way, that serology studies turned up an 80% attack rate among non-mask-wearers suggests that herd immunity probably won't occur at 50%, but may take until 80%, since, well, it got to 80%!
That masks worked as well as they did *in a contained environment with tons of unavoidable close contact* is pretty remarkable. I would have bet against masks doing much in this scenario.
Wow too bad we were told not to wear masks for about 2 months. 
I would think singing would be very difficult in an effective self-protective (N95, FFP2 or better) mask. The inhalation of air would be too restricted, & exhalation too unless one wore one with an exit valve, which exposes others to one's unfiltered breath.
This shows that masks are effective when distancing isn't possible, but I think other research has shown that physical distancing would be much more effective (more than masks) in a less contained environment.
It depends on the type of masks. We've known
for months that N95/FFP2 masks are highly effective against #SARSCoV2pic.twitter.com/FBKqxIO34J
What KIND of masks? That seems quite important, but isn't mentioned. Maybe they had N95s.
Why? If masks capture droplets, which they do, then most effective in close quarters, less necessary if more than 6’ apart.
Twitter may be over capacity or experiencing a momentary hiccup. Try again or visit Twitter Status for more information.
