Our theoretical analysis demonstrates that, in the cities that saw double-peaked autumn epidemics, control measures may have been, if anything, too effective, stopping transmission so effectively that substantial numbers of susceptible individuals remained in the population when controls were lifted. This remaining susceptible pool allowed transmission to restart, leading to another epidemic peak and (in some cases) to the resumption of interventions. Conversely, cities in which transmission had been continuing for longer before interventions were introduced saw much smaller or no second epidemic peaks, because insufficient susceptible people remained to restart transmission. The theory of imperfect interventions tells us there is an optimal middle ground, i.e., interventions tuned to give a single peak of minimal size.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1849868/
We don’t need n-95 masks.
ping!
All types of masks reduced aerosol exposure, relatively stable over time, unaffected by duration of wear or type of activity, but with a high degree of individual variation. Personal respirators were more efficient than surgical masks, which were more efficient than home-made masks. Regardless of mask type, children were less well protected. Outward protection (mask wearing by a mechanical head) was less effective than inward protection (mask wearing by healthy volunteers).
Meanwhile, I've been gearing up to go self employed again this year restomodding old trucks and will be sandblasting, sanding, grinding, welding etc. I have one nasty N95 mask and just spent two hours looking for replacement filters for it. Nope, nada, zilch.(Made in Mexico, not China too) Finally got a hold of a local welding supply co and they have a P100 respirator and filters so I'm heading up to grab a mask and extra filters. It's the dual cartridge type. Guy said he's been getting tons of calls about masks. They supply Doe Run Mining so I imagine corporate set stock aside to make sure they'd have something for them. There's gonna be a lot of people sanding and grinding with no lung protection this year. Everyone will be doing it Mexican style aka bandana. Wet bandana for painting.