Two EP Monthly editorial board members square off on a controversial topic.
Editor-In-Chief Salim R. Rezaie, MD debates Senior Board member William Sullivan, DO, JD, on the need for masks as an effective and necessary tool in helping to stave off the Coronavirus pandemic.
The key is how you define work. Clearly the effect of a recommendation to wear a mask does not equate to people wearing or wearing a mask correctly for that matter. This was evidenced by the DANMASK trial  where there was a <50% compliance rate reported.
Wearing masks by themselves will not get us out of this pandemic, nor will it ever get us to 100% in the prevention of COVID-19 transmission. You know what else doesn’t get us to 100% prevention? Vaccines. What is important however is that each layer of protection we provide to ourselves becomes additive. Therefore, we wouldn’t expect mask wearing alone to make a huge difference, but if you get vaccinated and wear a mask there is likely some additive benefit at reducing risk.
One thing I have not heard Bill discuss is the prevalence of disease or the density of the population that was studied in all his references. If there is low prevalence of disease and/or a low density of the population, then you would not see a large effect with masks, but it doesn’t mean there is no effect. On the other hand, if there is a higher prevalence of disease or dense population, you would expect to see a bigger impact from the masks.
Now that all that is out of the way, why did I start off by saying masks do work? Masks are aimed at reducing transmission, but do have some protective effects for the wearer as well. When you have a virus that can infect seven to eight people for every person that is infected, this is not negligible. Additionally, the issue with COVID-19 is there are people walking around asymptomatic just shedding virus. The biggest issue with Bill’s arguments against masks is that he is arguing masks don’t protect the person wearing them.
In a simulated study by the CDC,  medical procedure masks alone blocked 56.1% of particles from a simulated cough and a cloth mask alone blocked 51.4%. To put it simply, masks substantially reduce exposure from infected wearers (i.e. source control) and reduce the risk of potential exposure of the uninfected wearer.
Show me the evidence you say. In a meta-analysis  of six randomized clinical trials, involving four countries showed that wearing a mask was associated with a significantly reduced risk of COVID-19 (OR 0.38; 95% CI 0.21 to 0.69). In the subgroup of healthcare workers, the protective effect of masks was even more obvious (OR 0.29; 95% CI 0.18 to 0.44). In another metanalysis , 12 randomized trials and 21 observational studies on the effectiveness of face mask use against respiratory virus transmission was performed. It concluded the estimated effect masks could have is a reduced risk of infection by around 6% to 15%.
There is lots of compelling evidence that masks work. Even a limited effect on transmission would justify their widespread use in the middle of a pandemic to reduce overwhelming our healthcare systems and more importantly prevent some deaths. This is especially true when prevalence of disease is high and when in poorly ventilated, crowded settings. Don’t let perfect be the enemy of good.
- Bundgaard H et al. Effectiveness of Adding a Mask Recommendation to Other Public Health Measures to Prevent SARS-CoV-2 Infection in Danish Mask Wearers: A Randomized Clinical Trial. Annals of Internal Medicine 2020. [Link is HERE]
- Brooks JT et al. Maximizing Fit for Cloth and Medical Procedure masks to Improve Performance and Reduce SARS-CoV-2 Transmission and exposure. MMWR 2021. [Accessed 02/27/2021] http://dx.doi.org/10.15585/mmwr.mm7007e1
- Li Y et al. Face Masks to Prevent Transmission of COVID-19: A Systematic Review and Meta-Analysis. Am J Infect Control 2020. PMID: 33347937
- Brainard J et al. Community Use of Facemasks and Similar Barriers to Prevent Respiratory Illness Such as COVID-19: A Rapid Scoping Review. Euro Surveill 2020. PMID: 33303066
Masks are Ineffective
I will also begin this debate by stating that masks work … in filtering spittle. Unfortunately, ample evidence suggests masks have no effect on limiting respiratory virus transmission.
First, consider simple physics. Smoke particles average 400-700 nm in size. Coronavirus and influenza are one quarter the size of a smoke particle, measuring about 120 nm. If you can smell smoke through a mask, you are also inhaling viruses into your respiratory tract – you just can’t smell them. Even OSHA acknowledges that surgical masks “can only be used to protect workers from contact with the large droplets made by patients when they cough, sneeze, talk or breathe.”
Just like smoke wafting through a crowded bar, tiny respiratory virus particles remain suspended in the air for hours in enclosed spaces, which assures that mask-wearers and anti-maskers alike are inhaling respiratory viruses. A recent analysis funded by Florida housewives (!) showed school children’s masks contained many deadly bacteria (like MRSA, Serratia, and N. meningiditis), but an amazing lack of viruses. Ubiquitous cloth masks may even promote virus transmission.
A study by MacIntyre et al. showed the rate of influenza-like illness in participants using cloth masks was 10 times higher than participants using medical masks and three times higher than the control arm of the study. Do we really think masks will decrease COVID spread in classrooms?
Masks also won’t work because few people use masks as they were intended. People repeatedly touch their masks and most people change masks less frequently than they change their underwear. The WHO recommends changing masks every time they are touched, displaced from the face, or used with patients on contact or droplet precautions – like all those people with potential respiratory virus infections.
Yet some providers use the same mask for days to weeks. Using the same contaminated mask between successive patient visits will inevitably spread potentially deadly viruses and bacteria on the mask’s surface to every subsequent patient each time a physician exhales. The WHO discourages mask use by healthy people in the general public to avoid creating a false sense of security, increasing risk of self-contamination, allowing micro organisms on the mask to multiply, and causing headaches or respiratory issues.
Fortunately, Salim’s concerns about masks protecting against asymptomatic COVID spread have already been addressed. A study of 10 million Wuhan residents showed that asymptomatic COVID spread doesn’t exist. In 10 million residents, there were 300 cases of asymptomatic COVID and no spread to 1,174 close contacts of those residents. 
Multiple other studies show masks have no effect on respiratory virus transmission. Jacobs et al. showed that surgical masks have no effect on transmission of colds (i.e. rhinoviruses and “other” coronaviruses) but did tend to cause headaches.
A review of 17 studies by bin-Reza et al. showed no conclusive association between mask use and protection against inﬂuenza infection.  A 2021 study by Guerra showed no difference in COVID spread during COVID-19 surges between states that had mask mandates and those that did not. Oregon COVID cases increased 78% in one month after mask mandates were implemented.
Data from the Kansas Department of Health and Environment showed Kansas counties with mask mandates had higher incidences of COVID than those without mask mandates. The KDHE was then caught distorting the data points to create a false impression that mask use decreased COVID spread. 
Masks aren’t harmless. They act as a reservoir for filtered microorganisms that may enhance disease spread. They create side effects in some users, create a false sense of security in many users, add more than $300 billion to the costs of global medical care, and 1.6 billion of them ended up polluting our oceans last year alone.
This isn’t a case of perfect being the enemy of good. We can’t let faulty assumptions be the enemy of science. Asserting that our current practice of using ineffective over worn masks somehow decreases spread of COVID or any other respiratory virus has little physiologic or scientific rationale.