So How Well Did Masks Actually Work Against Covid-19?

Masks have been highly controversial and some of their biggest flash points have taken place on planes, from passengers getting ejected over not wearing them to the continued U.S. federal mask mandate for transportation when mask requirements are lifted in most other situations.

I argued that mask opponents should have been mask proponents, that they should have been touted as the conservative alternative to lockdowns. Though I also think the mask requirement on planes is no longer necessary.

So what do we actually know about the effectiveness of masks? First it’s important to separate out the ways that masks can help,

  • Source control. Whether masks keep someone who is infected from spreading the virus
  • Protection for the wearer. Whether masks keep someone who is wearing a mask from catching the virus

We rarely distinguish the types of masks for this analysis, although Lufthansa banned cloth masks and required KN95, KF94, or N95 masks. I have long written that if you were going to wear a mask you should get a decent one and learn to wear it properly.

We know that masks are highly effective against disease transmission in hospital settings, so why is it controversial elsewhere? People are using low quality masks and not wearing them properly so it’s not surprising that effectiveness would wane. Is this an argument against masks, or an argument for better masks?

There have been plenty of past studies on masks, showing their effectiveness and questioning their effectiveness. Many of these pre-dated the specific virus at issue, Covid-19, and many Covid-19 studies assumed transmission models such as respiratory droplets (that would be easier to stop than aerosols).

What’s really useful then is a new paper that does a fantastic job analyzizing data on Covid-19 transmission and mask–wearing to find that masks can reduce virus transmission by about 25% where there’s near-universal adoption, but that looking at where masks are mandated has little correlation with where high levels of mask-wearing takes place. Here’s a tweetstorm explaining the findings. (HT: Marginal Revolution)

Analyzing mask effectiveness is different than analyzing mask mandate effectiveness. And masks can help but they aren’t a magic bullet. This assumes the masks that people actually wear, not the potential effectiveness of using better masks, at least level 3 procedure masks if not N95s.

Just telling people they had to wear masks was a mistake. The policy focus should have been on supplying better masks and teaching people how to wear them effectively.

About Gary Leff

Gary Leff is one of the foremost experts in the field of miles, points, and frequent business travel - a topic he has covered since 2002. Co-founder of frequent flyer community, emcee of the Freddie Awards, and named one of the "World's Top Travel Experts" by Conde' Nast Traveler (2010-Present) Gary has been a guest on most major news media, profiled in several top print publications, and published broadly on the topic of consumer loyalty. More About Gary »

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  1. There never was and never could be enough high quality medical masks available for the general public to use even if the public could be taught to properly use them. Strategies that work for professionals do not necessarily translate to the general public, regardless of the subject. Having a bunch of medical professionals, some of which were and are still trying to cover up more than the public’s faces, was and is part of the problem.

  2. You fail to acknowledge that wearing masks was made into a partisan issue by those at the top of government, when it never should have been.
    In your ideal world we would each have access to N95 masks and have the knowledge to use them properly like medical professionals. This was never achievable so long as putting on masks was equated with losing our liberties.

  3. Putting on masks should have been a waybto retain liberties.

    Inadequate KN95s werr still better than cloth and non-medical N95s were broadly available by fall. Of course major internet sites continued to block their dusplay based on outdated information and brute force algorithms.

  4. Obviously a lot of mask wearing was nonsense (eg outside in a near empty park), some was great but the real benefit was as a reminder to behave judiciously. Those of us who preferred not to catch the disease did – and, to some extent, still do – need to be reminded to be careful around others. It’s not natural and therefore needs reinforcement.

  5. pete,
    Fauci himself flip flopped on mask wearing and those that raised objections to wearing of homemade or cloth masks did so based on science… and that science still supports them. It isn’t political to raise legitimate scientific concerns even if the objections end up falling along party lines.

    I was tested multiple times, took care of myself, used common sense, and never managed to “catch” covid. I am thankful and know not everyone – esp. seniors and those in the care of someone else – couldn’t make those choices.

    For the vast majority of people worldwide, covid was and still is a risk for people with a subset of conditions and the elderly and it is precisely because mandates such as mask wearing for everyone didn’t make sense.

    Covid was one of the very few diseases where public health officials attempted to create a one size fits all solution to what is still a pretty targeted disease.
    It should be clear that the number of people that won’t get vaccinated still see covid that way, even if there are many that will miscalculate at the cost of their lives.

  6. Plenty of people move in social circles where they continue to wear masks everywhere not because of the virus but because they don’t want others to think they are Republican-supporting in any way.
    Not making this up; people readily give this excuse.

  7. I don’t see wearing a mask being a political issue in Asia. Only in America and Europe.

  8. I am here with Gary: the masks are somewhat helpful but only when proper masks are chosen and certain protocols are followed. Some of the best advises given at the beginning of the pandemic were: (1) wash your hands especially after touching objects outside your immediate environments and (2) do not touch your face. Most of the folks constantly adjust the masks with their hands. This is equivalent to (a) spitting on your hands and touching other objects and (b) getting all the germs from the surfaces directly on your face. You have to wear those masks as a surgeon to make them work.
    At the beginning of the mask madness, my employer distributed some single use masks to wear. After wearing such a mask for < 30 min, I have developed a rush around my mouth and an inflammation behind my ear to the point that I have to Tylenol just to sleep. The employer response was that I should go to an emergency room (which I did not in the middle of pandemic). Examination of those masks revealed that they were shedding particulates, dust, and who knows what. I am fine but be aware of what kind of junk product you put on your face.

  9. N95 masks were banned in my adopted country- Panama. I have no clue why, but mine now sit in a drawer. And much of the population here is extremely poor and lost informal jobs as cooks, cleaners, gardeners, etc. due to Covid. Welfare was non-existent and was added in response to the pandemic. It’s $140 USD per month per family- while the poor tend to have huge families here, so it’s hard to feed them on this much money. It’s also not enough for unemployed 3rd World poor to buy masks, so they use whatever dirty cloth that they can find to make masks or re-use paper ones for long periods. So, I’m sure these people face more likelihood of becoming sick from wearing dirty masks vs. whatever level of protection they get from Covid.

    Yet, it’s W.H.O. recommendation that countries like Panama mandate masks. So, absolute mask mandates continue in poor countries like Panama, because international aid flows to 3rd World governments (and governments in the developing world don’t have a track record of wisely spending large inflows of cash!) if W.H.O. recommendations are followed.

    And the vax widely available in Panama is Astra Zeneca donated by the USA because it was deemed too dangerous to use on American Citizens. The message from the USA is horrible. This vax kills our valuable American people, so we’ll give it to you sub-humans in the 3rd World. I have seen that you advocated by for donating USA Astra Zeneca doses to developing counties, but I think the message it sends is appalling and makes the USA look ghastly.

  10. Masks are not that effective because of the poor quality, poor fit, and poor compliance.

    N95 masks are tight and uncomfortable, particularly in hot weather. I get it. However, I still use N95 masks on selected occasions.

    If there were 100% compliance with good practices (near lockdown, mask wearing, vaccination), Covid would be over. There is still a lot of bad practices. I heard of someone rushing to a restaurant a day before a lockdown. No, the virus doesn’t observe lockdown dates. People are also saying “is this allowed, a gathering of ___ number of people?” No, if there is a Covid pandemic, you should think in terms of more safety, not doing the worse things that are still legally permitted.

  11. Stick too your expertise. Expert scientists have stated that masks are worthless. Plenty of proof for that. You are embarrassing yourself.

  12. “Putting on masks should have been a way to retain liberties.”

    I agree with Gary here. It should have been embraced by the crazy right wing in order to keep open the economy and stop so many people from dying. But the right wing in this country only embraces policies that directly contribute to their pockets and/or power.

    The whole Fauci flipped thing that nuts like Tim continue to repeat over a year afterwards has been explained many times. For those on the short bus who didn’t grasp it, at the beginning of the pandemic he was trying to avert a rush on N95s so that medical professionals would have access to them. It was a stupid thing to say but it was reversed many months ago. It doesn’t excuse the willfull ignorance of the repubikkkan party and their Dear Leader, who would have died from covid but for extraordinary medical treatment that is not available to the general public.

  13. ps if a nurse or doctor can wear an N95 mask for hours in a surgery room, I think you can manage it for 30 minutes in a grocery store, snowflake.

  14. The messaging and approach was all wrong. Ordering people to wear a mask all the time just led to people wearing it wrong all the time and then getting “fatigue” over the message. It would have been better to promote wearing the mask properly where it does some good and not worrying about people walking in a park wearing it or not. Unfortunately the nature of government is not to educate or facilitate but rather to order and exert authority. I’m not sure they know how to approach anything in any other manner.

  15. @Rober M
    @Doug Weneck
    You are talking about the so-called scientists that support Chump and have been de-bunked by the real scientists.
    Masks work and I continue to wear two masks living in the worst state when it comes to Covid because of the lackadaisical governor who also caught Covid and survived. Now the Delta variant is taking hold in this state and again this governor is sitting on his ass.
    Another “Chump Fool” on this site.

  16. @Gary – yep, exactly. Now we’re going to be hearing all sorts of scaremongering correlations with respect to vaccination – 70% of people hit by lightning or struck by a bus had gotten the vaccination, etc…sigh.

  17. Robert M,
    you made the conversation political, not me.
    If a public health leader gives one advise and then changes it, then that forever harms his credibility and has nothing to do with politics.
    And the public was never told to wear N95s so your argument makes no sense.

    Other public health leaders continued to maintain that masks for the public didn’t work while others said they did. I can accept divided advise – the results will prove whether they were right or not – but I don’t look kindly on people that say they are experts changing their minds repeatedly.

    and you still miss the point that covid was never equally dangerous to all of the population – just like every other disease – and yet the US and most of the world adopted a one size fits all approach to dealing with a disease which many people don’t believe is a threat to them.

    Instead of trying to argue about who is more political, why don’t you address the root issue of expecting all of the world to do something that affects a relatively few to a serious degree?

    Instead of imposing mass restrictions on the general public, impose them on the most vulnerable with strong warnings for those that are not comfortable to stay home.

    And that is precisely the issue that the airline industry has to deal with. Business travelers are not going to return until there is a general sense of safety – and masks say there is not safety. Masks have led to more conflict which makes travel less appealing to those that have a choice, including high value passengers.

    The obvious way forward is not to try to analyze the past as if we can fix it but to recognize that the vaccines work, people have a choice to take them or not, and it is not society’s job to protect people who don’t do what is in their best interest – just as is true regarding illicit drug use, membership in gangs, smoking or excessive drinking or any number of other choices we all make.

  18. “The policy focus should have been on supplying better masks and teaching people how to wear them effectively.” Umm yea sure Gary. Because the anti-maskers problem with masks was that the masks weren’t good enough or that they weren’t told how to wear them properly. What a bunch of nonsense. Masks were made political and there are segments in the US population that never will wear them because they are following the some defunct leader who made it seem like there was something wrong with wearing a mask. These are the very same idiots who when they are gasping on their death bed as a result of catching covid argue with the medical staff and continue to insist that covid isn’t fatal.

  19. FOX News’ Tucker Carlson urged his viewers on April 26 to confront strangers wearing masks request they bare their faces by telling them, “Your mask is making me uncomfortable.”

    So yeah, teaching him how to use a mask would have made a difference. Sure.

    And then this gem: “Your response when you see children wearing masks as they play should be no different from your response to seeing someone beat a kid in Walmart,” Carlson said on his Monday show. “Call the police immediately, contact child protective services. Keep calling until someone arrives.” He went on: “What you’re looking at is abuse, it’s child abuse and you are morally obligated to attempt to prevent it.”

    It’s all because he didn’t know how to use a mask.

  20. The idea that masks work is, frankly, a joke. Look at the hundreds of charts @ianmsc has posted on twitter in the past year and tell me they work. It’s preposterous. And the data just confirms the well established pre-Covid science. I suppose if everyone (impossibly) wore a FITTED respirator everywhere maybe masks could do “something.” But in the real world, all they do is virtue signal and make people fearful (which seems to be one of the PURPOSES of mask mandates).

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