Even some reviews from this year find little efficacy with widespread usage of cloth masking, e.g.: https://aapsonline.org/mask-facts/
The Association of American Physicians and Surgeons is an explicitly political anti-universal healthcare lobbying group that has previously supported research claiming HIV doesn't cause AIDS, that there is a link between abortion and breast cancer, and that vaccines cause autism.
In general, it's tough to find significant correlations between any measured mandated NPI and growth rate in cases, which you can play with here: https://ourworldindata.org/grapher/government-response-stringency-index-vs-biweekly-change-in-confirmed-covid-19-cases?time=2020-11-30..latest
It's disingenuous to correlate mandated NPI and growth rate in cases across countries that have such different cultural associations with mask-wearing and public health. In Japan, for instance, the government did astonishingly little, but there has been a culture of mask-wearing when you have a cold for decades, so people wore masks without government interference.
I don't understand the inclination to pretend that THE SCIENCE is so ironclad either: before this year, it was highly debated whether for both in medical settings, and in population settings, widespread use could work to stop the spread of disease.
This is demonstrably false. This year THE SCIENCE has significantly more incentive to study the effects of mask-wearing at population levels, thus leading to more conclusive studies. But, there are numerous peer-reviewed studies from the past decade supporting the use of masks in healthcare workers and community health contexts:
In 2013:
https://pubmed.ncbi.nlm.nih.gov/24229526/Results: The median-fit factor of the homemade masks was one-half that of the surgical masks. Both masks significantly reduced the number of microorganisms expelled by volunteers, although the surgical mask was 3 times more effective in blocking transmission than the homemade mask.
A study in 2014 found that the reason face-masks didn't work to contain influenza in the past is because NOT ENOUGH PEOPLE WORE THEM.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4293989/ Outside the hospital environment, the effectiveness of facemasks in containing the spread of airborne diseases in the general population has been diminished largely due to improper use and lack of user compliance... Another Australian study found that while adherence to mask-wearing significantly reduced the risk for influenza-like infections, less than 50% of the participants in their study wore facemasks regularly.
A study in 2015 summarized previous studies, showing mask usage is useful in both healthcare and community settings:
https://pubmed.ncbi.nlm.nih.gov/25858901/Several randomised clinical trials of facemasks have been conducted in community and healthcare settings, using widely varying interventions, including mixed interventions (such as masks and handwashing), and diverse outcomes. Of the nine trials of facemasks identified in community settings, in all but one, facemasks were used for respiratory protection of well people. They found that facemasks and facemasks plus hand hygiene may prevent infection in community settings, subject to early use and compliance.
More in 2010:
https://pubmed.ncbi.nlm.nih.gov/20092668/ There is some evidence to support the wearing of masks or respirators during illness to protect others, and public health emphasis on mask wearing during illness may help to reduce influenza virus transmission.
In healthcare settings in 2014:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4294054/For a novel respiratory virus that could potentially cause severe disease with reports of transmission to healthcare workers, a good and cost-effective way to prevent its transmission in the healthcare setting is through barrier precautions, which include the use of gloves, gowns and masks.
The debate, to the extent which it existed, has always been about which masks block against specific strains of various diseases, not whether masks are generally useful. Masks have been known to be useful for a century.
And then this year, looking at peer-reviewed scientifically backed health journals specifically studying the 2019-coronavirus, there is ample evidence that masks are important tools for controlling this pandemic:
https://pubmed.ncbi.nlm.nih.gov/32917603/ We have demonstrated a simple optical measurement method to evaluate the efficacy of masks to reduce the transmission of respiratory droplets during regular speech. In proof-of-principle studies, we compared a variety of commonly available mask types and observed that some mask types approach the performance of standard surgical masks, while some mask alternatives, such as neck gaiters or bandanas, offer very little protection.
https://www.medrxiv.org/content/10.1101/2020.10.05.20207241v3 An N95 respirator blocked 99% of the cough aerosol, a medical grade procedure mask blocked 59%, a 3-ply cotton cloth face mask blocked 51%, and a polyester neck gaiter blocked 47% as a single layer and 60% when folded into a double layer. In contrast, the face shield blocked 2% of the cough aerosol. Our results suggest that face masks and neck gaiters are preferable to face shields as source control devices for cough aerosols.
https://www.medrxiv.org/content/10.1101/2020.08.11.20145086v1 Whether manikin or human, wearing a face covering decreased the number of projected droplets by >1000-fold. We estimated that a person standing 2m from someone coughing without a mask is exposed to over 1000 times more respiratory droplets than from someone standing 5 cm away wearing a basic single layer mask. Our results indicate that face coverings show consistent efficacy at blocking respiratory droplets.
https://pubmed.ncbi.nlm.nih.gov/32624649/We use qualitative visualizations of emulated coughs and sneezes to examine how material- and design-choices impact the extent to which droplet-laden respiratory jets are blocked. Loosely folded face masks and bandana-style coverings provide minimal stopping-capability for the smallest aerosolized respiratory droplets. Well-fitted homemade masks with multiple layers of quilting fabric, and off-the-shelf cone style masks, proved to be the most effective in reducing droplet dispersal. These masks were able to curtail the speed and range of the respiratory jets significantly, albeit with some leakage through the mask material and from small gaps along the edges.
And even in studies specifically acknowledging that there are many flaws in mask studies, the conclusion is evident:
https://www.nature.com/articles/d41586-020-02801-8Nevertheless, most scientists are confident that they can say something prescriptive about wearing masks. It’s not the only solution, says Gandhi, “but I think it is a profoundly important pillar of pandemic control”. As Digard puts it: “Masks work, but they are not infallible. And, therefore, keep your distance.”
And in peer-reviewed journals, evidence also shows wearing masks has also led to decreasing case-counts:
https://www.healthaffairs.org/doi/10.1377/hlthaff.2020.00818?utm_medium=email&utm_source=Newsletter&utm_campaign=MEDIA+ADVISORY%3A+Wehby+FT+AOP+6-11-20&utm_content=From+Health+Affairs%3A++Mask+Use+Could+Prevent+200%2C000%2B+US+COVID-19+Cases&stream=top& Mandating face mask use in public is associated with a decline in the daily COVID-19 growth rate by 0.9, 1.1, 1.4, 1.7, and 2.0 percentage points in 1–5, 6–10, 11–15, 16–20, and 21 or more days after state face mask orders were signed, respectively. Estimates suggest that as a result of the implementation of these mandates, more than 200,000 COVID-19 cases were averted by May 22, 2020. The findings suggest that requiring face mask use in public could help in mitigating the spread of COVID-19.
https://www.cdc.gov/mmwr/volumes/69/wr/mm6940e3.htmThe number of COVID-19 cases stabilized and began to decrease approximately 2 weeks after local officials began mandating mask wearing (throughout several counties and cities) and enhanced sanitation practices.
https://www.cdc.gov/mmwr/volumes/69/wr/mm6947e2.htm?s_cid=mm6947e2_w Masks are an important intervention for mitigating the transmission of SARS-CoV-2 (1–6), and countywide mask mandates appear to have contributed to the mitigation of COVID-19 spread in Kansas counties that had them in place. Community-level mitigation strategies emphasizing use of masks, physical distancing, staying at home when ill, and enhanced hygiene practices can help reduce the transmission of SARS-CoV-2.
The CDC agrees:
Experimental and epidemiological data support community masking to reduce the spread of SARS-CoV-2. The prevention benefit of masking is derived from the combination of source control and personal protection for the mask wearer. The relationship between source control and personal protection is likely complementary and possibly synergistic14, so that individual benefit increases with increasing community mask use.
The WHO agrees:
Masks are a key measure to suppress transmission and save lives.
Masks should be used as part of a comprehensive ‘Do it all!’ approach including physical distancing, avoiding crowded, closed and close-contact settings, good ventilation, cleaning hands, covering sneezes and coughs, and more.
Depending on the type, masks can be used for either protection of healthy persons or to prevent onward transmission.
Masks help. Masks alone are not a cure-all. Keeping case counts down until a vaccine is ready by wearing masks regularly, maintaining social distancing when practical, and minimizing indoor contacts with people outside your household will help Quinnen Williams to be able to play in front of a full stadium in 2021.
Also MB - I was a line cook for over seven years until September when I finally finished up my pre-reqs in order to start my doctoral-level healthcare degree full time. No need to pee on food service workers by implying we can't understand science.
