So this is why we were told to wear masks that were ineffective at blocking viruses? In short, we effectively went mask-less for the duration and spreading was relatively minimal; certainly not mitigated by disposable masks.

This was also interesting:

Back to School in a Rapidly Changing World

https://play.prx.org/listen?ge=prx_12369_085cdf46-2a33-4f24-...

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JumpCrisscross a day ago | parent [-]

> why we were told to wear masks that were ineffective at blocking viruses?

Masks and HEPA filters can block droplets that contain viruses. Neither filters out actual virus particles.

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vintermann a day ago | parent [-]

Respiratory virus particles outside an aerosol droplet don't last long, but yes, they should be filtered too (not "blocked", it will always be probabilistic)

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JumpCrisscross a day ago | parent [-]

> they should be filtered too (not "blocked", it will always be probabilistic)

The article’s point is we haven’t precisely studied what those probabilities are.

	▲	vintermann a day ago \| parent [-]
		No it isn't actually, those kind of low level technical questions have been somewhat studied. It's the end to end interventions which have been poorly studied.