Throughout the course of this pandemic, there has been widespread confusion, misunderstanding, and anxiety about COVID-19—from how it is transmitted, how dangerous it is, and how to protect yourself from it. Now, the latest topic of debate is whether or not the Centers for Disease Control and Prevention recommend double-masking, and like other COVID-19 debates, misconceptions abound.
The use of masks as a simple infection control measure has become a controversial and polarizing issue. Now, a new push to wear not one, but two masks at once threatens to make it even worse. But does it even make sense?
Protective masks are a lightweight and easy tool for reducing the chances of spreading respiratory pathogens from one person to another. Illnesses (such as COVID-19) are caused by respiratory viruses and are transmitted by our breaths.
Thus, it makes sense that placing a filtering barrier in front of our respiratory orifices would reduce the spread of respiratory viruses.
Nearly every locality in the United States now mandates wearing masks in situations where you are exposed to other members of the public, and 96% of the population is willing to wear a mask when they leave the house or come into contact with other people, according to a survey taken in December 2020.
Despite this, the rate of known cases, hospitalizations, and deaths due to COVID-19 reached unprecedented levels this past fall. The rate of hospitalizations alone eclipsed the summer spike by a two-fold factor.
The conclusion to draw from this is that masks may indeed help in certain situations, but on their own they simply were insufficient to stem the spread of the virus in the past few months.
We seem to be on the downward slope of the present spike, as cases and hospitalizations have been on a sustained decline since January, and deaths have begun trending downward more recently, but it likely has little to do with masks, since they have been so broadly accepted or already mandated in so many places since before the fall spike.
So if one mask isn’t working very well, why not wear two?
That is the conclusion many are drawing from the recent CDC study. To unpack this study correctly, we must first understand that the CDC was testing different ways of wearing masks to improve their performance—it was not simply testing the efficacy of double-masking exclusively.
Here’s what the CDC found. Unsurprisingly, when a mask is better fitted to a person’s face, fewer aerosols and particulates escape past it. In a trial where a source (a person coughing or breathing) and a receiver (the person from which aerosols were measured) wore two masks (a cloth mask worn over a medical procedure mask,) the receiver was exposed to 96.4% less aerosol.
On its own, this is an interesting finding, but is impossible to be generalized to a policy on how we ought to comport ourselves during the present pandemic.
One problem is that this study only tested one type of procedure mask and one type of cloth mask. Procedure masks are fairly standard (although there are different strap types), but the market for cloth masks includes an endless variety of fabrics and forms. Outside of the ideal conditions of a laboratory, someone who opts to wear a cloth mask on top of a procedure mask would lose all the benefits of improved filtration if, for example, the cloth mask was poorly fitted to the face. If, for instance, a cloth mask has poor fitment, it would do nothing to improve filtration, and the purpose of the double mask would be negated.
Another problem is that the aerosols in the experiment are not an exact representation of viral particles, but of a person’s respirations. How infectious a person’s respirations are would depend on his or her viral load.
Thus, a reduction in exposure, as measured in the study, does not necessarily mean the same reduction in infectiousness.
The study authors themselves recognize that these findings are not to be interpreted “as being representative of the effectiveness of these masks when worn in real-world settings.” Indeed, to reduce the point of the study as to simply a trial of the effects of double-masking would be far too narrow an interpretation—in reality, the results only speak to the effectiveness of the particular masks used.
As every person has a unique face, masking, double-masking, or other modified mask-wearing could all work to varying degrees. The only true conclusion from this study is not that we should all wear two masks, but that better fitting masks filter our breaths better.
To that end, wearing a properly fitted N95 respirator would do just as well as double-masking, or rather, better. The greatest potential utility of masks is when people who are possibly exposed find themselves in situations where physical distancing from strangers is impossible—for instance, while walking past others in a grocery store aisle.
But masks were only ever meant to be part of a broad mitigation strategy. They were never meant to seal us off from the dangers of the world.
If people want to wear two masks, they should certainly do so, but everyone must remember that masks only make up one part of a broader mitigation strategy, which includes assessing risks, social distancing, testing, and importantly now, vaccinating. Policymakers should remember this, rather than rely on masks and make them even more unappetizing to use.
And policymakers should explore additional options—like widespread rapid self-testing—which is an even more promising way to battle the pandemic.
It has been over a year now since SARS-CoV-2 first arrived on our shores, and Americans have been asked to avoid buying masks, to wear masks, and, now, to wear two masks. We’ve learned many things over the course of 2020, but at no point did we learn that masks would be anything other than an adjunct to better, more effective measures.
Doubling up on masks, at this point, would be doubling down on one of the least effective measures we now have.
This piece originally appeared in The Daily Signal.