Obviously it's good advice to wear masks in public when confronted with a respiratory disease capable of asymptomatic transmission for days after infection. The masks don't make any one person safer, but widespread usage makes us all safer.

Trouble is, there weren't enough masks at first. It's not clear that there are now, for that matter.

One of the few things Trump is correct about is that the WHO has bungled this situation at pretty much every step of the way. So no, it's not OK for YouTube to tie their policies to WHO directives. They're a US company, so they should be referring to CDC guidelines (1) instead.

1: https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-si...

There weren’t enough N95 masks. There were plenty of ad hoc/DIY masks.

That’s exactly right

There were enough surgical masks

You could double or triple them up if you thought they were not effective enough

The velocity of a particle that could get through that would not be enough to infect a person two feet in front of you

This should be obvious

The CDC guidelines you’ve linked to continue to say surgical masks should be for medical personnel.

This is ridiculous!! A mask is a cloth on a string. We are how many months into this thing... why hasn’t our private industry created enough cloths on strings???? What is the shortage? Is it the cloth?

It’s because the politicians were reactionary and behind on the most basic things every step of the way. Why not order American companies to produce a billion masks and mail them to every building in bulk?? Save trillions of dollars later.

FWIW I found reading about the process of making respirators quite fascinating. It opened up a whole world of reading about nanofibers and the melt blown process that I'd not previously stumbled upon. Turns out good masks aren't just any old fabric - producing unwoven sub-micron nanofiber fabric is quite involved and that fabric is in short supply.

Exactly this. Parent to your comment has no firm grasp on how difficult and expensive it is to place and maintain a melt-blown-fiber shop outside of a crisis, let alone during one.

That said : cotton DIY masks can be quite effective. I recommend buying a box of shop towels, which are made with a similar blowing mechanism that creates a random fiber orientation.

The CDC is making a distinction between surgical masks and non-medical grade masks, which is fine. They will both reduce the likelihood that an asymptomatic person will transmit the disease, but the former should be reserved for medical personnel when possible.

The WHO doesn't appear to be drawing any such distinction, at least at first glance.