Face masks effectively limit the probability of SARS-CoV-2 transmission • Hacker News Board

Re: Face masks effectively limit the probability of SARS-CoV-2 transmission

#221

Post by fighterpilot » Fri, May 21, 2021, 3:55 AM UTC

in_cahoots wrote: post #213

fighterpilot wrote: post #175

Earlier quoted context omitted.

True, but there was many other reasons to think masks would work. Its demonstrated efficacy in other coronaviruses and the cultural evolution of dense Asian countries to use masks as a way to combat virus transmission. The WHO and CDC behaved liked total idiots, setting the burden of proof way too high for what should've been a pragmatic, common sense decision made with some uncertainty. Not atypical of bureaucrats t…

I don’t think they were total idiots, at least not from the angle you’re pointing out. The CDC knew masks were effective, but they wanted to make sure masks were reserved for healthcare workers. Remember at the time nurses were given a single mask to use for multiple days, and many hospitals had drives to collect donated masks. The CDC lied to prevent the general public from making the situation worse. Was it worth t…

It's hard to attribute the same charity to the WHO. They were dragged kicking and screaming to mask recommendation and this happened many, many months into the pandemic, well after any concerns of mask shortages were alleviated.

I see your point about the CDC. But they should've recommended home made masks. Other countries did that. They messed up big time. It's impossible to know the counterfactual with perfect confidence, but we can make a sound judgement given what we know.

Re: Face masks effectively limit the probability of SARS-CoV-2 transmission

#222

Post by m4rtink » Fri, May 21, 2021, 3:57 AM UTC

admax88q wrote: post #212

mhb wrote: post #97

Earlier quoted context omitted.

3M 8210s are US $26 for 20 now. $1.30 per mask seems pretty reasonable to me, but I've never bought them in industrial quantities so don't have that anchor. I've worn N95s for hours (actually P95s which have a nicer seal) and I agree that they're less comfortable than less effective alternatives. But it is a bit curious that people are concerned enough to be wearing their homemade mask alone in a car or walking outsi…

I wear mine alone in the car or on the sidewalk frequently. Not because I'm "afraid" but because I'm too lazy to take it on and off between every stop I'm going to make. This attitude that people are wearing masks alone because they're afraid and/or stupid is toxic.

Not to mention fervently touching mask surface that could be contamination might not be a good idea, especially if there is a chance you might then touch your eyes.

Re: Face masks effectively limit the probability of SARS-CoV-2 transmission

#223

Post by kadoban » Fri, May 21, 2021, 4:03 AM UTC

mhb wrote: post #105

mulmen wrote: post #72

Earlier quoted context omitted.

If you tell me how something works and it fits within my mental model of the world then I will trust you. I will add this information to my mental model of the world. If you tell me something works but can't explain how I will consider if the claim is worth evaluating then attempt to understand it myself before accepting it. If you tell me to trust you with no explanation I will immediately distrust you.

That's reasonable and also what I would like. But what is the mental model of someone wearing their mask alone in the woods or in their car? So, yes, we should explain why an N95 is better than a handkerchief, but it seems like there are plenty of people who don't care about the details and just need to be told that one is more effective.

The mental model of many wearing masks "alone" is that it's more annoying to take the mask on and off all the time than it is to just leave it on. Also, touching the mask constantly leads to concerns about contaminating your hands and then spreading that.

Re: Face masks effectively limit the probability of SARS-CoV-2 transmission

#224

Post by ganoushoreilly » Fri, May 21, 2021, 4:04 AM UTC

simpleguitar wrote: post #179

nimish wrote: post #144

Earlier quoted context omitted.

Nope. It's circular. We need actual tests in the wild, not models.

During an interview with some of the doctors sent into Wuhan in their wave, they claimed none of the 10 thousand or so doctors sent in became infected. They used strict PPE protocol, including N95 masks. Given what we know about the covid transmission now, it was absolutely the N95s that prevented these doctors from getting infected.

Alternatively it could also be flawed data on infections, which we know is already highly likely.

Re: Face masks effectively limit the probability of SARS-CoV-2 transmission

#225

Post by unishark » Fri, May 21, 2021, 4:04 AM UTC

bellyfullofbac wrote: post #102

slver wrote: post #71

Earlier quoted context omitted.

Bless your soul, but what I've learned from the way we handled the pandemic worldwide (and are still handling it) is that information that's readily available and should in theory reach everyone, flows ridiculously slowly, even among specialists and political figures, it's easily corrupted and distorted, and a loud ignorant minority counts as much in the public discourse, as the voices of millions of reasonable peopl…

Yeah, it's disappointing to see how I still see people wearing their masks incorrectly, e.g. just over the mouth and not covering their noses. Sometimes I think human beings are advanced, but then I walk into a public toilet and I see evidence how many are still no better than animals. It's a simple technology, urinate into the hole where the water can wash it away and we'll remain hygienic, but a lot of people still…

This is just something that happens with masks. I think you're reading too much into it.

In years past in Japan, where mask-wearing was always common, I noticed that just covering the mouth and not the nose was quite common. It still covers most of what people are trying to cover (odor, droplets). Which would still help for the worst contributors to covid too. If people are feeling claustrophobic or legitimately having difficulty breathing, I think it's an acceptable compromise.

Also, if people are talking a lot, then the mask tends to get pulled down off the nose constantly due to jaw movement. Hence in Japan you'd see store clerks and people in such roles often wearing the mask that way. Also this happens practically every word for many kinds of cloth masks. So if you see a public speaker somewhere with a fancy cloth mask not covering their nose (a shaming target I've noticed on twitter etc.) they probably can't help it.

Re: Face masks effectively limit the probability of SARS-CoV-2 transmission

#226

Post by nimish » Fri, May 21, 2021, 4:05 AM UTC

simpleguitar wrote: post #179

nimish wrote: post #144

Earlier quoted context omitted.

Nope. It's circular. We need actual tests in the wild, not models.

During an interview with some of the doctors sent into Wuhan in their wave, they claimed none of the 10 thousand or so doctors sent in became infected. They used strict PPE protocol, including N95 masks. Given what we know about the covid transmission now, it was absolutely the N95s that prevented these doctors from getting infected.

Then run a proper randomized controlled trial with comparisons to cloth and surgical masks so we have actual data, not 10000 anecdotes.

This was the biggest event of the last 50 years, we can throw a few billion at a real trial.

Re: Face masks effectively limit the probability of SARS-CoV-2 transmission

#227

Post by refurb » Fri, May 21, 2021, 4:22 AM UTC

joshuaengler wrote: post #74

The VAST majority of mask wearing I have seen in California has been average cloth-covers. I have only seen a handful of people out of thousands actually wearing N95 masks, so perhaps N95 is highly effective at stopping viruses, but I see basically nobody wearing that. Stores, offices, buildings, all are completely fine with you wearing a bandana over your face. There is effectively no point in even mandating mask la…

The other thing to consider is fit. When I needed a mask for workplace safety, I had to get a fit test done - otherwise you leave massive gaps around the edge of the masks that lets unfiltered air in and out.

I think surgical masks do a good job in containing droplets from a cough or sneeze, but if there are airborne particles, I doubt they do much. A good fitting N95 probably helps in that department.

Re: Face masks effectively limit the probability of SARS-CoV-2 transmission

#228

Post by apgwoz » Fri, May 21, 2021, 4:29 AM UTC

AshWolfy wrote: post #191

crocodiletears wrote: post #187

Earlier quoted context omitted.

In the US, it's more to do with the way the CDC's messaging throughout the pandemic than any rejection of the evidence concerning a mask's efficacy. People refusing to wear masks rarely question whether or not it works, and more to do with a low estimation of the disease's threat, as well as contempt for both the technocrats who chose to mislead the public about masks early on, and leaders who they believe are overst…

As someone who worked the public for the entire pandemic, id say it was about 50-50 between people who thought covid wasnt a threat and people who thought masks werent effective

who _has_ or who _did_? I take one of these as “the pandemic is over” which seems far from the case, generally...

Re: Face masks effectively limit the probability of SARS-CoV-2 transmission

#229

Post by panarky » Fri, May 21, 2021, 4:38 AM UTC

__blockcipher__ wrote: post #163

panarky wrote: post #135

Earlier quoted context omitted.

> The effectiveness of masks, however, is still under debate Effective for the mask wearer, or effective for others in the vicinity of the mask wearer? It's well established that cheap cloth masks and procedure masks don't protect the mask wearer very much. The rationale for cheap masks is that they drastically reduce the spread of particles from the wearer to everyone else nearby . If your goal is to protect yoursel…

Except there is no convincing evidence that they actually do help others, and the whole theoretical mechanism is centered around catching large respiratory droplets which is at odd with the totality of evidence pointing towards aerosol being the dominant mode. I would add if droplet transmission is the dominant mode, which I very much doubt, then masks would still fail in a real-world setting when you look at the fac…

> no convincing evidence

This MIT study [0] was pretty convincing.

They conclude that "face masks can be an extremely effective indoor safety measure".

For example:

If an infected person was riding on a commercial airline with 100 other people, other passengers would be at risk of infection within 70 minutes. If all of the passengers wore masks, however, that space could be safe for up to 54 hours.

[0] https://www.pnas.org/content/118/17/e2018995118

Re: Face masks effectively limit the probability of SARS-CoV-2 transmission

#230

Post by kenneth » Fri, May 21, 2021, 4:40 AM UTC

boplicity wrote: post #178

andreygrehov wrote: post #155

Earlier quoted context omitted.

> observational data show that regions or facilities with a higher percentage of the population wearing masks have better control of the coronavirus disease Which is also not entirely true. There are quite a lot of regions (data from worldometer, statista) that have a better control of the virus despite people not giving a crap about face masks. For instance, Florida has 1600 deaths/M vs 3000 deaths/M in New Jersey.…

I don't understand this myth about Florida. It has fared very badly in the pandemic. You're three times as likely to have died in Florida from COVID, as opposed to in Canada. It sits in the middle of the States, in terms of death rates, which overall have been among the worst in the world. Compare your example to an area where people really take masking serious, such as Hong Kong, and then maybe you'll have a valid c…

I live in Hong Kong. The mask mandate here is entirely pointless, and has not made any difference to our handling of the pandemic.

What has on the other hand is extremely aggressive tracing, tracking, and quarantining of all potential contacts. I've had a few friends who were unlucky enough to get caught up in a cluster, and the ones who caught it got out of the hospital far quicker than their contacts got out of their government quarantine. Rather aggressive tactics, but it's effective.

But it's obvious that masks had nothing to do with it. There are plenty of unmasked activities (dining, drinking etc) that haven't spawned clusters, while masked activities (gym, dance club) spawned our big clusters.