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Masks Save Lives

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Masks save lives

Reminding others that “masks save lives” isn’t just sound advice. It’s a scientific fact that wearing one in public can help to slow the spread of SARS-CoV-2, the virus responsible for the coronavirus disease 2019 (COVID-19) pandemic.

I’m very careful to wear a mask outside my home whenever I’m out and about. I do it not necessarily to protect myself, but to protect others. If by chance I’ve been exposed to the virus and am currently incubating it, I wouldn’t want to spread it to other people. And any of us could be an unknowing superspreader. We owe it to everyone we encounter, especially those who are more vulnerable, to protect them. As my NIH colleague Tony Fauci recently demonstrated, it’s possible to wear your mask even while you’re outside exercising.

But there are still skeptics around. So, just how much does a facial covering protect those around you? Quite a bit, according to researchers who created a sophisticated mathematical model to take a more detailed look [1]. Their model shows that even if a community universally adopted a crude cloth covering that’s far less than 100 percent protective against the virus, this measure alone could significantly help to reduce deaths.

These findings, funded partly by NIH, were published recently in Nature Communications. They come from Colin Worby, Broad Institute of MIT and Harvard, Cambridge, MA, and Hsiao-Han Chang, National Tsing Hua University, Taiwan.

The researchers noted several months ago that recommendations on wearing a mask varied across the United States and around the world. To help guide policymakers, the researchers simulated outbreaks in a closed, randomly interacting population in which the supply and effectiveness of crude cloth or disposable, medical-grade masks varied.

Under different outbreak scenarios and mask usages, the researchers calculated the total numbers of expected SARS-CoV-2 infections and deaths from COVID-19. Not surprisingly, they found that the total number of deaths and infections declined as the availability and effectiveness of face masks increased.

The researchers’ model primarily considered the distribution of medical-grade, surgical masks. But because such masks are currently available in limited supply, they must be prioritized for use by health care workers and others at high risk. The researchers go on to note that the World Health Organization and others now recommend wearing homemade face coverings in public, especially in places where the virus is spreading. While it’s true the ability of these face coverings to contain the virus is more limited than medical-grade masks, they can help and will lead to many fewer deaths.

Another recent paper also suggests that while wearing a mask is primarily intended to prevent the wearer from infecting others, it may also help lower the dose, or inoculum, of SARS-CoV-2 that the wearer might receive from others, resulting in milder or asymptomatic infections [2]. If correct, that’s another great reason to wear a mask.

Already, more than 175,000 people in the United States have died from COVID-19. The latest estimates [3] from the Institute for Health Metrics and Evaluation (IHME) at the University of Washington’s School of Medicine, Seattle, predict that the COVID-19 death toll in the U.S. may reach nearly 300,000 by December 1.

But that doesn’t have to happen. As this new study shows, face coverings—even those that are far from perfect—really can and do save lives. In fact, IHME data also show that consistent mask-wearing—starting today—could save close to 70,000 lives in the months to come. Saving those lives is up to all of us. Don’t leave home without your mask.


[1] Face mask use in the general population and optimal resource allocation during the COVID-19 pandemic. Worby CJ, Chang HH. Nat Commun. 2020 Aug 13;11(1):4049.

[2] Masks Do More Than Protect Others During COVID-19: Reducing the Inoculum of SARS-CoV-2 to Protect the Wearer. Gandhi M, Beyrer C, Goosby E. J Gen Intern Med. 2020 Jul 31.

[3] New IHME COVID-19 forecasts see nearly 300,000 deaths by December 1. Institute for Health Metrics and Evaluation. August 6, 2020.


Coronavirus (COVID-19) (NIH)

Colin Worby (Broad Institute of MIT and Harvard, Cambridge, MA)

Hsiao-Han Chang (National Tsing Hua University, Taiwan)

NIH Support: National Institute of Allergy and Infectious Diseases


  • Noel McDevitt says:

    Thank you, Dr. Collins ..please continue your work and your efforts to continue the informational and educational activity of the NIH to inform the public of the most current scientific reports and the practical application of this information. Hopefully, all our fellow citizens and our leaders will listen and include the recommendations into daily life.

    • Ron Psimas says:

      Obviously, no one is following the newest area of interest, Nasal Physiology, and no one has interviewed the vast number of Healthcare workers who are complaining of Chest pains, decreased O2 levels in their blood, break outs around the mouth and on the face from the increase of bacteria trapped under the mask and on the face.
      Masks are not a substitute for hand washing and fresh air. The constant wearing of mask in the dental industry will show up as more patients arrive in the offices with increasing decay issues and increases in periodontal disease.

  • tbn says:

    nice information.

  • Amy D says:

    Thank you for providing a scientific basis to an issue that has been debated endlessly it seems.

  • Victor Janzen says:

    Thank You for these blogs, Dr. Collins. Much appreciated.

  • DR. SAUMYA PANDEY, PH.D. says:

    Masks save lives…an expert opinion!

  • vahid says:

    Thank you, Dr. Collins for this helpful article. As you mentioned, wearing a mask plays a key role at preventing the coronavirus.

  • Jacqueline Guillory says:

    Thank you Dr. Collins for this useful information. Since I began wearing a mask in late March, I’ve been spared the inevitable colds that usually go around and around my household and my work place. Another good thing about wearing masks.

  • robert moor says:

    Many thanks Dr Collins for your clear and informative blogs on covid19 and especially this one on the hotly debated issue of masks and their value.

  • chandrasekharan parambath says:

    Masks saves lives ….is a useful campaign…….Thank you for the information

  • M waller says:

    All of your data is a what if… Can you show data with proof that herd immunity is not the better answer for the healthy population under 65yrs and no co-morbidities.

  • Chuck Rains says:

    I am confused. In the first paragraph you state that masks will slow the infection rate. But by the end of the article you state that masks will save lives. And, as an earlier comment, what about the problems that are created from long term wear.

  • Brandon says:

    The first study listed here and used as evidence for the unfounded claim that “masks save lives” is a mathematical model, not a real-world study based on actual observations. All referenced studies seem to be based on opinion and speculation. What are the long-term effects of reuptake of trapped respiratory bacteria and fungi due to mask wearing?

  • M. says:

    Nice post … The use of face covers protect against community transmission of Covid-19.

  • Leslie G. says:

    I am home. I can go outside to take a walk but have yet to understand the risk of walking while I am wearing a mask passing others who are not wearing a mask. In my neighborhood I might pass 6- 10 people on a street 15 ft wide. Not one of those 10 people will be in a mask. How risky is that to me? PLease please please answer this question for me so that I might enjoy some freedom in walking or enjoy some freedom from recognizing that I shouldn’t be walking.
    Please don’t use general terms like “where appropriate”; lessen the risk: low risk; better than…
    PLease tell me the risk is very low, or not/ Statistics and percentages would be terrific as your very low and my very low might not be synonymous. THANK YOU!

  • C.Epright says:

    What suggestions might the experts have for reducing skin and mouth infections for those who must wear masks all the time for their jobs?

  • John says:

    I have a problem with authority.

  • SR says:

    Face masks are not foolproof protection from the COVID-19 virus strain, but it is still better than not wearing a mask. It acts as an essential layer to physical distancing, worn while following the 6 feet distance rule and basic hand hygiene.

  • susan says:

    I would love to buy an NIH mask. I’ve been making three-ply masks at home with a filter pocket, but the NIH has a great message. Can you make them available to the general public?

  • Tyson says:

    Thank you for sharing this valuable information. Sharing these sort of messages to the public at this point of pandemic is so appreciated. Because I am sad to say that people are not concerned about proper wearing of masks. Many of them are even ignorant about the fact that they are not only causing trouble to themselves but also harming the people around them. As mankind is striving hard to develop a medical solution for this COVID 19, wearing a mask and maintaining social distance could help to control the spread of disease . . .

  • Sam Tsang says:

    Thank you for sharing this valuable information. . .

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