The Case for COVID Mask-Wearing

"SARS-CoV-2 has the protean ability to cause myriad clinical manifestations, ranging from a complete lack of symptoms to pneumonia, acute respiratory distress syndrome, and death. Recent virologic, epidemiologic, and ecologic data have led to the hypothesis that facial masking may also reduce the severity of disease among people who do become infected. This possibility is consistent with a long-standing theory of viral pathogenesis, which holds that the severity of disease is proportionate to the viral inoculum received. Since 1938, researchers have explored, primarily in animal models, the concept of the lethal dose of a virus — or the dose at which 50% of exposed hosts die (LD50). With viral infections in which host immune responses play a predominant role in viral pathogenesis, such as SARS-CoV-2, high doses of viral inoculum can overwhelm and dysregulate innate immune defenses, increasing the severity of disease. Indeed, down-regulating immunopathology is one mechanism by which dexamethasone improves outcomes in severe Covid-19 infection. As proof of concept of viral inocula influencing disease manifestations, higher doses of administered virus led to more severe manifestations of Covid-19 in a Syrian hamster model of SARS-CoV-2 infection."

Monica Gandhi, M.D., M.P.H., George W. Rutherford, M.D. The New England Journal of Medicine

Law enforcement trainees wearing protective face masks as they take notes while being trained on how to handle civil disputes during class at San Bernardino County Sheriff’s Frank Bland Regional Training Center in San Bernardino on Wednesday, July 29, 2020. (Photo by Watchara Phomicinda, The Press-Enterprise/SCNG)

"If facial coverings decrease the amount of virus a person is infected with, they can provide a way of tilting towards infections that result in minimal or no symptoms, yet induce some degree of immunity."

Dr. Amesh Adalja, infectious disease expert, senior scholar, Johns Hopkins Center for Health Security, Baltimore

 

"If this theory bears out, population-wide masking, with any type of mask that increases acceptability and adherence, might contribute to increasing the proportion of SARS-CoV-2 infections that are asymptomatic."

Dr. Monica Gandhi, Dr. George Rutherford, University of California, San Francisco

 

"Covering mouths and noses with filtering materials serves 2 purposes: personal protection against inhalation of harmful pathogens and particulates, and source control to prevent exposing others to infectious microbes that may be expelled during respiration. When asked to wear face coverings, many people think in terms of personal protection. But face coverings are also widely and routinely used as source control. For instance, if given the choice between having surgery performed by a team not wearing some covering over their mouths and noses vs a team that does, almost all patients would reject the former. This option seems absurd because it is known that use of face coverings under these circumstances reduces the risk of surgical site infection caused by microbes generated during the surgical team’s conversations or breathing. Face coverings do the same in blocking transmission of SARS-CoV-2."

John T.Brooks, M.D., Jay C.Butler, M.D., Robert R.Redfield, M.D. Jama 

Masks -- the public is informed by authorities urging the use of facial coverings in this time of SARS-
CoV-2 disease roiling the world order -- are essential to protect others in the event you harbour the virus and have not displayed symptoms of COVID-19. There is also, health experts inform us, a good measure of protection for the mask-wearer from contracting the virus. On the other hand, a recent paper reflecting research published in The New England Journal of Medicine posits that mask wearing may have another residual and very important outcome.

Within communities where infection is widespread and many have yet to be diagnosed while shedding infectious droplets, mask-wearing which cannot entirely prevent some degree of infection penetration, by allowing a small amount of the virus to infect in essence acts as a vaccine. Allowing one's immune system to respond to trace amounts of infection without becoming overwhelmed by a large dose of infection. This is called variolation and its effect on a broad scale is to produce a kind of community 'herd effect'.

Masks, by limiting the amount of viral particles reaching tissues of those newly infected are then serving to inoculate more than massively infecting. In virology, the authors of this new paper explain, there is a tradition called the "LD-50" of a virus; the amount of an infection scaled to body mass that will produce great harm to those exposed to a full load. Viral disease toxicity may be dependent on "dose"; the lesser the dose the lesser the damage, enhancing opportunity for the body's immune system to adapt and fight the intruder.

Verification through research and observation appears as indirect evidence that SARS-CoV-2 doses if moderated through the preventive use of masks could produce a far less harmful outcome. A Japanese-led study that found "higher doses of administered virus led to more severe manifestations of COVID-19 in a Syrian hamster model of SARS-CoV-2 infection", appears to bear out the two authors' contentions.

Mask-wearing is now the norm in South Korea.Photo: Wonseok Jang 

Countries practising high-masking compliance are seen to have considerably lower rates of severe COVID-19 and consequent death numbers while resulting in fewer hospital admissions. The authors suggest that since being taken up as a first line of defence, (social isolation and mask-wearing), the result has been a mass protocol of "mask variolation". The original method of vaccination where fluids from smallpox patients were collected, to expose the non-infected to harmless amounts of diseased matter to induce mild infection providing immunity; hence variolation.

Health authorities early in the first wave of COVID believed that non-symptomatic people would not significantly shed as an infection source, until experience proved otherwise and then there arose an urgency to cope with the reality that asymptomatic carriers of the virus were indeed shedding infectious particles to the same degree as those infected with the virus who exhibited a wide range of symptoms. 

The message that the latest published research is delivering is that the eventual agreement that mask-wearing represented an integral approach to prevention ended up making far more of an impression in avoidance than might have been anticipated. The wearing of masks has proven successful in shielding the wearer from heavy infection doses, while the small amount of viral infection that did penetrate the shields has proven to have far-reaching consequences in making the wider public less susceptible to serious infections requiring hospitalization, while serving to reduce the death rate.

 

A line of people on Montgomery Street in San Francisco waits to get masks during the 1918 flu pandemic. Failure to wear a mask was punishable by imprisonment or a fine. Photo courtesy of the California History Room, California State Library, Sacramento.