Let's Just Get Every Face Covered

Photo by cottonbro at pexels.com

In the over decade-long history of this blog, Dan's recent post, A Tiresome SPAT, has been viewed more times than any other post we've ever written. And it's only been up 48 hours. This is a testament to Dan's ability to encapsulate the controversy regarding SARS-CoV-2 transmission in a billiant way. As I reflected on his writing, it became increasingly clear to me that the source of the controversy of whether we are dealing with droplet transmission or aerosol transmission is deeply rooted in the framework through which you're viewing the issue. These frames are associated with different values and ways of thinking, and depending on the frame utilized determines your recommmendations for mitigating transmission.

The first framework I'll describe is the medical (i.e., individual patient) frame. Imagine a patient visiting their physician and asking what they can do to best avoid COVID-19 infection. In addition to social distancing and hand hygiene, the physician would likely recommend a mask and eye protection. The physician might even recommend an N95 respirator depending on the patient's underlying conditions, the context of their exposures, and the patient's risk tolerance. In general, in this framework, risk tolerance is low, and the goal is typically to reduce the individual's risk to the irreducible minimum. This approach drives the occupational health perspective. PPE is viewed from the standpoint of efficacy--how do we provide ideal protection?

Now, let's look at the public health (i.e., population) framework. From this perspective, the goal is not necessarily to prevent every possible case of COVID-19, but rather to bring the outbreak to an end. This requires reducing the R0 to less than one. Thus, the interventions don't need to be perfect, and individual risk is tolerated to a somewhat greater degree. And in this framework, the PPE recommended is that which is most effective (i.e., how well does it work in the real world?), which factors in adherence. Let's say that face covering A is 90% efficacious, but only 20% of people are willing to wear it. On the other hand, face covering B is 60% efficacious, but 80% of people are willing to wear it. We're clearly better off with face covering B. The public health framework is driven by a utilitarian perspective--accomplishing the greatest good for the population, not for any given individual patient. 

Our recent JAMA viewpoint, Moving Personal Protective Equipment into the Communnity, in which we argue for universal face shields in the community settting, was written from a public health framework. This was perhaps not clear to the many individuals who pointed out that in some cases there could be airborne transmission of the virus for which a face shield may not work. Yes, we get that, but the epidemiology convinces us that the airborne route is a minor mechanism of transmission.

The bottom line here is that we can't let perfect be the enemy of the good. We recommend influenza vaccine every year despite an average seasonal effectiveness of approximately 40%. The best face covering is the face covering that people will wear. Though I personally favor face shields for community use, I am happy to see faces covered in almost any way possible (which is why I love the photo above). 

And if it's not bad enough that experts are not in agreeement, we have the additional problems of botched messaging by the CDC and political leaders who by intentionally sowing doubt and refusing to be good role models, make this work all the harder. Kudos to those leaders who are mandating face coverings. And my message to everyone is this: for community settings, let's just get everyone in a face covering now, whichever one works for them. After the pandemic is over, we can sort it out once and for all. 


  1. I appreciate the perspective of this blog. I work at a as an interpreter at a hospital and when I read about the debate re: airborne vs. droplet it can be very confusing. In fact, much of the information that is out about COVID is confusing and/or sometimes downright contradictory. Thanks for taking the time to explain things in a rational way.

  2. "The Strategic Importance of Broadly Using the Appropriate Face Shields by the General Public in Precluding the Severe Infection by New Coronavirus"

    In view of the most important and proven ways of transmission of the infection caused by SARS-CoV-2 and noticing the size and weight of the virus (which are more than those of some similar viruses), applying the appropriate ordinary face shields by the general public in the usual spaces can be very useful.

    ► To tackle some possible problems in using an appropriate face shield, if needed, the face shield could be applied together with a very simple and washable cover of the mouth mainly to facilitate the face shield application.

    Some considerable weak points of the ordinary face masks, usually applied by the general public in most times, are known. The ordinary face masks, contrary to the special face masks, are penetrable; but the face shields are not so. Even a simple, ordinary face shield covers the eyes too. The ordinary face shields, compared to the ordinary face masks, are considerably more effectual and handy, as well as washable and thus economical for the general public in the long-term.

    Obviously, applying the face shield does not mean ignoring other necessary recommendations like hand-washing, etc. Likewise, having a face shield, better than having a face mask, precludes touching the face, too.

    ● It is clear that the use of protective equipment by healthcare workers must be given priority over their use by the general public. Anyhow, if a piece of equipment, like the face shield, could be effectual for healthcare workers, why we do not recommend a piece of similar equipment for the general public too. In the case of the general public in the usual spaces, we do not necessarily need the special face shields. In this case, even a suitable ordinary face shield can be very helpful.

    An appropriate simple face shield can be used for a long time. It is effectual, handy, accessible, and economical. [Anyway, if you work in a high-risk department or center, such as Intensive Care Unit (ICU) or the like, you must use all necessary equipment, including the special face shields, the special face masks (like N95), etc.]

    ● Making a good balance between the economy and health, especially in the long-term, is very important. Especially in the long-run, social precluding (barricading), e.g. via broadly using the suitable ordinary face shields by the general public, in its turn, can be practical and helpful in making such a vital balance.

    Regarding a realistic and integrative attitude, "Social Precluding (Social Barricading)" can have a determining role in helping to preclude the severe infection and sepsis caused by New Coronavirus (SARS-CoV-2). It can feasibly be fulfilled via broadly using the appropriate ordinary face shields, even the simple and homemade shields, by the general public.

    Naturally, emphasis on social precluding does not mean ignoring the benefits of "Social Distancing". Social precluding and social distancing could be considered within the framework of an integrative attitude. Social precluding can compensate for many possible defects of social distancing in practice, too. If social precluding could be applied together with social distancing, it could be ideal. Anyway, whether social distancing is appropriately applied in practice or not, social precluding can be and must be applied in any case.

    ● The effectiveness of the appropriate face shields in precluding the infection has been proved; however, urgently conducting more studies, also including the laboratory investigations, to provide as many academic documents as possible is highly recommended. [Incidentally, the effects of simply applying some special transparent coatings, like nano-silver coatings, on the special and even ordinary face shields to combat Covid-19 virus could be, then, studied.]

    Thanks for your attention.

    K. E (MD)


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