1y ago

Face mask effectiveness: What science knows now

www.cbsnews.com

In an interview for 60 Minutes, CBS News chief medical correspondent Dr. Jon LaPook posed that question to Linsey Marr, a Virginia Tech University professor specializing in aerosol science.
"They are very helpful in reducing the chances that the person will get COVID because it's reducing the amount of virus that you would inhale from the air around you," Marr said about masks.
No mask is 100% effective. An N95, for example, is named as such because it is at least 95 percent efficient at blocking airborne particles when used properly. But even if a mask has an 80% efficiency, Marr said, it still offers meaningful protection.
"That greatly reduces the chance that I'm going to become infected," Marr said.
Marr said research shows that high-quality masks can block particles that are the same size as those carrying the coronavirus. Masks work, Marr explained, as a filter, not as a sieve. Virus particles must weave around the layers of fibers, and as they do so, they may crash into those fibers and become trapped.
Marr likened it to running through a forest of trees. Walk slowly, and the surrounding is easy to navigate. But being forced through a forest at a high speed increases the likelihood of running into a tree.
"Masks, even cloth masks, do something," she said.

Not that I expect most people to believe it at this point...

137 comments

The people that need to know this- won’t listen, and the people that don’t need to know- don’t need to know because they already know it.
- It's not about the morons that refuse to wear mask. It about people that believes in truth checking that the things they know are correct. If we wore masks and never tested if that did anything we would be as stupid as any anti-vaxxer.
  
  Yea but there was already ample evidence. This isn't enlightening anyone with anything new. (not that revalidation is bad, but revalidation isn't changing anything)

Even if the research had come out that masks did absolutely nothing to protect against Covid, I would have absolutely no regrets for masking up. We did what we thought was the right thing based on the evidence available and it harmed no one. The worst that would’ve happened if we were wrong (outside of a false sense of security) is that we looked silly for awhile. The people that were vehemently against wearing masks were tool-sheds who were manipulated into their position by an Administration who assumed it would affect Democratic-leaning cities/states more and who are so blinded by their anti-science views that they didn’t even understand the threat posed by Covid. Mask wearers did the right thing and the evidence backs us up. Anti-mask idiots hopefully learned an evolutionary lesson, but I doubt it has really ever sunk in.
- I remember reading a while back that MAGA counties had significantly higher death and serious disease rates. Probably still do. I'm not sure about the apartment Republican strategy of actually working to kill their core voters, but I guess we'll see how it works out for them.
  
  I've read that TrumpCo wasn't as concerned with it out of the belief that more populous Democratic counties/states would be more heavily impacted by Covid. If anything, they tried to take advantage of Covid to use it as a natural bio-weapon and this is probably their worst, yet least talked about crime that they'll likely never face charges over. The strategy apparently blew up in their faces though, but by the time anyone realized, it was already too late to do anything about it. The damage had already been done.
  https://www.theguardian.com/commentisfree/2021/aug/07/republicans-treated-covid-like-bioweapon-turned-against-them
- Yup. I wiped my groceries down in the early pandemic. Turned out that probably wasn't needed, but it's a minor act that if the virus was in a different form could have helped.

The real problem for the Right Wing is that masks are at their most effective stopping the wearer's germs from getting OUT, even though they're also pretty effective at stopping others ' germs from getting IN. They can't stand the idea of sacrificing even a tiny bit of comfort for anyone else to benefit. Even if it also helps themselves.

So fucked up masks became politicized: I had hoped that the pandemic would help normalize them so people would just mask up whenever they feel sick. It could've mitigated the spread of all sorts of airborne disease.
Instead, they've been demonized by insane fascists. What a stupid world we live in...
Sometimes I just wear a mask to piss them off lol.
- God I remember when this happened.
  Right at the beginning of the pandemic, masks were being recommended by the CDC and everyone just sort of did it. COVID was novel and we were still trying to wrap our heads around it and being over cautious.
  Weeks earlier, Trump was lamenting his polling numbers and complained that he didn't have a "Katrina" that would rally his favorables.
  Trump could have done something simple and just worn the damn mask. He could have told people that until they had better data, let's be cautious and following the CDC guidelines.
  But when he was asked point blank, he said he wouldn't wear one.
  Before that, conservatives and liberals were wearing masks. It wasn't a "tribal" signal. But the second he said it, it was. You could tell immediately after that who conservatives were.
  The funny thing is had Trump handled COVID better, he probably would have won re-election. Or at least it would have been closer.
  But nope. That's not the kind of person he was.
  
  He could have made a MAGA mask and told his cultists that it was more effective and blessed with holy water or something, and then go on to make piles of cash. At the time, that's what I was expecting to happen, but sadly I was wrong.
  
  Unfortunately, the recommendations from most (all?) top-level officials in the US right at the beginning of the pandemic was for the general public NOT to wear masks (including Dr. Fauci, Dr. Birx, etc). This absolutely didn't help matters when later they had to change their tune and recommend then mandate masks, after they had said that they were not needed.
  Here's a nice compilation video of these statements over the first couple of months of the pandemic: https://piped.video/watch?v=tRE59LJc6CA
  
  This is not what happened, they recommended people not to wear masks at the start. This might have undermined their later recommendation to wear a mask
  
  He would have had more voters at least.
- I'm Asian. So I could wear a mask and not get the stink eye even before covid.
  Things that should become obviously acceptable often doesn't seem to do so due to some sort of cultural acceptance.
  Like in regions most susceptible to malaria, they hate mosquito nets. Yet if I lived there, I'd mosquito net everything even without malaria!
- They're normalized in some places. I see people wearing them and not just the "Covid isn't over!" folks.
  
  I mean, COVID isn't over lol: It didn't go anywhere, we're just dying from it a little less often. Must be nice avoiding colds and flu if masks are common in your area though, getting sick sucks.
  
  Is COVID over though?
  
  I wore a mask in crowded places for three and a half years without getting sick. Then I stopped and two weeks later I got COVID. It wasn't much fun and it took weeks to get over. Maybe that was coincidence, but now we're back into flu season I'm wearing masks in crowded places again. I figure each person who wears one makes it a little easier for those who would like to but don't want to go against the social tide.
- If not wearing a mask meant only that person died, I'd be extremely happy to let the idiotic right wing die. Unfortunately, they affect everyone else.
  We really need to stop treating right wing extremism as the same "difference of opinion" tier as "i like my bedroom walls painted blue vs green".
- The problem is the cdc basically lied at the start and killed all their credibility before things even got started. Then you had apologists claiming they didn't lie, making everything even worse.
  
  It had (almost) nothing to do with the cdc. In other countries the same happened.
  Source: am german
  
  They did not provide the context, which was misconstrued as lying.
  Everyone did not need to wear a mask at first because it was not widespread enough for them to be effective for the general population compared to making sure medical staff who were far more likely to be exposed had masks. Masking by the general public at the very beginning was a waste of masks compared to just reducing the time spent in groups. It became effective as time went on and the mask supply ramped up.
  
  That was a problem, but I wouldn't say it was the problem.
  
  What is the specifics of the lie that they said?
  
  They literally didn't lie, the post is linked in this thread. Of course at the time people weren't linking the source, they were quoting part of one sentence and getting inflamed that half of a sentence seemed to say the opposite of what the actual post said.
  It literally says "not recommended -for the general public- at this time" how is that miscontrued to "they don't work"? It doesn't say that at all. In fact the video in that post, I know it's a full 30 seconds long and slow and boring... but the video specifically says to save them for medical professionals and others in close contact with the infected. Again very much stating specifically that they do help.

The fact that the idea of an air filter is controversial is frankly amazing.
They apparently only work in every situation except when put over your face.
- Many think that it takes only 1 virus to catch the disease when, in reality, your body will easily deal with a small amount of unknown pathogens and does so many times a day.
  Masks work because they reduce the overall viral load, so your immune system isn't overwhelmed.
  What also doesn't help is how unintuitively percentages scale. A mask that is 90% effective doubles the viral load if compared to a mask with 95% effectiveness, even tho the difference is "only" 5%.
  
  Influenza data shows that it takes about 1000 viral particles to infect a human. Assuming COVID 19 is similar, reducing viral load also significantly reduces severity of disease if you get it.
  
  Not only that but those percentages are for a given particle size. They will both stop 100% of ping pong balls, for instance. As mentioned in yoher comments, the virus is usually in aerosol, microscopic droplets of varying size.

There's something to be said for masks that aren't 100% effective that isn't often said: letting in a little virus when out in public, but not enough viral load to cause an infection, very likely has a positive effect on your immunity to the virus.
- Most people think it is an all or nothing thing, including some doctors.
  My immune system is apparently very good against noroviruses or whatever was giving my family the "all exits no waiting" treatment. A doctor argued that I must not have come in contact with the virus since I had no symptoms aside from feeling icky for a couple of hours. I was bothered that they had such a bad grasp on how viral infections work and I don't consider myself an expert by any stretch. Even after I told them I had been having to clean up my toddler and infant messes, do diapers, bathe them etc. I had come in contact with saliva vomit poo pee breath etc- of course I came in contact with it.
  I had the virus, I just didn't have the disease/nasty symptoms. Maybe I had built immunity, maybe I had been able to build immunity quickly, maybe insufficient viral critical mass for rapid onset- who knows?
  
  Yeah, I'm the same way, I always get about 10% as sick as the rest of my family when something is going around. I just assume my immune system is well trained. But I am also always cautious when new stuff is around, as an immune system can't be trained to stuff it hasn't seen yet. But I don't go for a zero tolerance approach. I go for a minimize exposure approach. Avoid contact with mucous membranes and other external weak points, and keep distance. But don't completely avoid everything. Still do stuff, just more carefully.
  
  “all exits no waiting”
  I'm stealing this.
  Norovirus is fucking EVIL. The worst part is your body doesn't maintain immunity indefinitely. Which is why people will often complain they get it seasonally.
  When I've had it I like to say "my organs have been liquified and my skin suit is blasting the soup out of both ends".
  Nothing worse than jetting hot shit out of your ass then puking into the bath at your side - repeatadly.
  Then when you're 'empty' you curl into a ball on the bathroom floor.

That's the same as what we knew about masks a century ago?
- I thought doctors and nurses were wearing this just for fun.
  
  All “Hygiene Theatre” .., according to Qult45.
  
  Seriously… if masks don’t work, then I’m sure you’ll have no problem with your surgeon coughing into your open chest without one on, right?
  
  I thought it's so that doctors don't lick the scalpels.

Assuming a mask blocks 50% of particles or droplets in either direction (preventing yours from escaping if you're sick, preventing outside particles from getting to you), when 2 people wear masks that reduces the chances of transmission in a given retail encounter by 75%.
Reducing those odds by that much, when (from an epidemiological POV) the biggest math factor is to drive the r number down below 1, it's a huge deal. If you do that consistently, the virus becomes rarer and rarer and has fewer opportunities to mutate and more importantly, you're feeding fewer and fewer human beings to it.

It's such a tired topic. Most pathogenes of this kind travel by attaching themselves to little droplets, aerosols and larger spit particles. Thinking that even cloth masks aren't at least reducing those to a certain degree by catching said particles just feels dishonest, and medically related masks have been in use in hospitals and other locations for ages. Do people think they are worn out of fashion? And now we've got even more studies and data that confirms all of this even more, but covidiots will just continue with their idiocy. 🙈🙉
I hope I won't have to witness an even deadlier disease turning into a pandemic, but at the rate things are going it is probably not very unlikely.
- If you are sick and breathing into your own mask and it catches your exhalations, helping reduce your contagiousness for others, and you touch your own germs to throw them away, others are still better off.
  If your only concern is protecting yourself then you need to use masks a bit differently, but they still offer improved protection over doing nothing.
  If you are still confused I doubt any more comments from me will help you.
  
  This article covers that. In fact, the article I linked is the article you commented on.
  Here's the part from the article.
  "Early in the pandemic, some guidance from health professionals suggested that wearing a mask might actually lead to infection: A person might encounter a contaminated mask and then touch their eyes, nose, or mouth. But research in the ensuing years has shown that fear to be misplaced.
  "There wasn't any evidence really that that happens," Marr said.
  Marr said her team aerosolized the coronavirus, pulled it through a mask, and then examined how much virus survived on the mask. The study reported some viral particle remained on some cloth masks, but no virus survived on the N95s or surgical masks.
  Marr's team also touched artificial skin to masks and looked at how many virus particles transferred to the artificial skin. No infectious virus transferred.
  "I hope the study kind of shows that it's something we don't need to worry about as much as we were told," Marr said."
  
  That makes no sense. All infected particles caught by the mask are particles that could've found their way into other peoples lungs instead.
  
  This might be the case with bacterial infections, but most viruses can't live that long without a host, especially if daylight is involved. ( L Meister · 2022 · Transmission of infectious SARS-CoV-2 via fomites is possible upon extensive moistening, but it is unlikely to occur in real-life scenarios). So if you're not touch your mask all the time, it should help defend against infection significantly

We know that they help prevent spreading disease to other People and that a large subsect of Americans hates that it helps others.
- We have known that masks help reduce the spread of diseases transmitted through the air for decades, they just have evidence it works for Covid specifically.
  
  Yes, that is indeed what I posted. The second half was the important part of the comment.

The problem isn't that "most people" won't believe it. The problem is that there is very little conversion of people who didn't already believe it. The ones who most need to understand this will flat out refuse to believe any kind of science on the matter, because being right is what is most important to them. Admitting they were wrong just isn't going to happen.
- That is part on Survival of the Fitist. Masks were a key component of that, as more intelligent humans wore masks during the peak of the infection. Within the human population with COVID-19, then, the “fittest” are individuals who mount a normal phase 1 and phase 2 immune response. This means a strong immune response in phase 1 to clear the primary coronavirus infection and inhibit its spread in the lungs. Those who have never had COVID-19 scientificly are the superior humans on a immunity scale. More likely to reproduce and pass those genes onto future generations. The less intelligent humans who refused to wear masks and didn't have strong immune responses died off, allowing more fit humans to reproduce thus saving humanity.
  
  This argument (if it is not sarcastic, it's hard to tell on the Internet) shows a fundamental misunderstanding of evolution and instead uses the language of social darwinism like "superior human".
  Evolution occurs in populations, not individuals. Furthermore, it doesn't have a "goal," it is just a natural process. Also, there are numerous ways different immune responses could be either advantageous or detrimental when combined with other variables.
  I'm also not convinced that intelligence correlates to refusal to mask; as a counterpoint, smart people are also very good at justifying whatever position they already hold.
  You won't find most modern biologist using the phrase "survival of the fittest," because it's more confusing than illuminating. The preferred expression is "natural selection."

Yeah but a guy on YouTube said they don’t work and he said “trust me” so what now?
- "you can still smell farts"
  sigh
  
  At the same time, you have the people claiming they immediately turn blue and pass out within seconds of putting a mask on.

This means nothing. I'd be willing to bet that anyone unwilling to wear a mask is also unwilling to listen to science/medical experts.
- Yeah... you've either got people who absolutely refuse to believe masks are effective, or you've got people that are so done with the whole thing that they just don't care anymore. Hearing an expert say they work isn't going to convince either of these groups to wear them.

"Science knows now that they were right for the past 3 years"
- More like decades if not centuries, since masks have been used in medical setting for a very, very long time.
  
  The plague doctor full body costume worked. Kept the fleas away, especially from the lungs, and any airborne bacteria. Sure, they thought that it was the scented shit they put inside the beak that was helping and that someone asking them to wash their hands was insulting, but either way, there was Renaissance PPE, and possibly even medieval PPE.

maybe the video is more informative than the article, but the article has no new science information in it.
- If anything its even spreading a very slight misinformation. The blown plastic material of n95 and similar masks doesn't operate in the way the article describes, they work on the principle of static electricity grabbing the particles as they pass through. If a mask loses its static charge, say, through washing, it loses a significant amount of its effectiveness.
  I'm not sure why it suggests that particles smash into the fibers (some do, but its the static electricity doing the heavy lifting.
  
  Articles are written at a 6th grade level. What you're describing requires a higher level of understanding.

But my freedoms!
/s
- Lockdown has made me realise that people don't crave freedom, they instead crave a lack of responsibility to a sociopathic level. They are unwilling to consider a greater good nor anything else beyond the immediate effect on themselves.
  
  Lockdowns were the single biggest attack on freedom we've seen in our lifetime. We can never let them happen again
  
  Lockdowns were economic warfare against the poor and working class, there was no greater good, only disaster.
  
  The lock downs were always going to be a failure. Stay-at-home measures should have been last resort due to harmful effects (the economic harms, the educational harms, the harms to access to healthcare, the harms to societal wellbeing … just the way we all function … and especially mental health).
  We destroyed and entire generation with lockdowns. Gen Z will never recover from that.

It's obvious masks did something. I didn't catch anything, not even a cold, until I took it off, but now having a weak as hell immune system
- You had a stretch of time with fewer infections and are just noticing what you used to go through with that contrast. Like when you leave a loud room for a bkt and go back it seems louder than when you left it the first time.
  
  Yes, that's literally what I'm saying. The mask prevented me from getting any disease and then got my immune system weakened because of that
- No way your immune system would be completely destroyed in just 3 years not getting sick
- No, you don't.

137 comments