Physical distancing, face masks, and eye protection to prevent person-to-person transmission of SARS-CoV-2 and COVID-19: a systematic review and meta-analysis

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes COVID-19 and is spread person-to-person through close contact. We aimed to investigate the effects of physical distance, face masks, and eye protection on virus transmission in health-care and non-health-care (eg, community) settings.


Face Masks Against COVID-19: An Evidence Review

The science around the use of masks by the general public to impede COVID-19 transmission is advancing rapidly. Policymakers need guidance on how masks should be used by the general population to combat the COVID-19 pandemic. Here, we synthesize the relevant literature to inform multiple areas: 1) transmission characteristics of COVID-19, 2) filtering characteristics and efficacy of masks, 3) estimated population impacts of widespread community mask use, and 4) sociological considerations for policies concerning mask-wearing. A primary route of transmission of COVID-19 is likely via small respiratory droplets, and is known to be transmissible from presymptomatic and asymptomatic individuals. Reducing disease spread requires two things: first, limit contacts of infected individuals via physical distancing and contact tracing with appropriate quarantine, and second, reduce the transmission probability per contact by wearing masks in public, among other measures. The preponderance of evidence indicates that mask wearing reduces the transmissibility per contact by reducing transmission of infected droplets in both laboratory and clinical contexts. Public mask wearing is most effective at stopping spread of the virus when compliance is high. The decreased transmissibility could substantially reduce the death toll and economic impact while the cost of the intervention is low. Thus we recommend the adoption of public cloth mask wearing, as an effective form of source control, in conjunction with existing hygiene, distancing, and contact tracing strategies. We recommend that public officials and governments strongly encourage the use of widespread face masks in public, including the use of appropriate regulation.


If 80% of Americans Wore Masks, COVID-19 Infections Would Plummet, New Study Says

There’s compelling evidence that Japan, Hong Kong, and other East Asian locales are doing it right and we should really, truly mask up—fast.


Universal Masking is Urgent in the COVID-19 Pandemic: SEIR and Agent Based Models, Empirical Validation, Policy Recommendations

We present two models for the COVID-19 pandemic predicting the impact of universal face mask wearing upon the spread of the SARS-CoV-2 virus one employing a stochastic dynamic network based compartmental SEIR (susceptible-exposed-infectious-recovered) approach, and the other employing individual ABM (agent based modelling) Monte Carlo simulation indicating (1) significant impact under (near) universal masking when at least 80% of a population is wearing masks, versus minimal impact when only 50% or less of the population is wearing masks, and (2) significant impact when universal masking is adopted early, by Day 50 of a regional outbreak, versus minimal impact when universal masking is adopted late. These effects hold even at the lower filtering rates of homemade masks. To validate these theoretical models, we compare their predictions against a new empirical data set we have collected that includes whether regions have universal masking cultures or policies, their daily case growth rates, and their percentage reduction from peak daily case growth rates. Results show a near perfect correlation between early universal masking and successful suppression of daily case growth rates and/or reduction from peak daily case growth rates, as predicted by our theoretical simulations. Taken in tandem, our theoretical models and empirical results argue for urgent implementation of universal masking in regions that have not yet adopted it as policy or as a broad cultural norm. As governments plan how to exit societal lockdowns, universal masking is emerging as one of the key NPIs (non-pharmaceutical interventions) for containing or slowing the spread of the pandemic. Combined with other NPIs including social distancing and mass contact tracing, a “mouth-and-nose lockdown” is far more sustainable than a “full body lockdown”, from economic, social, and mental health standpoints. To provide both policy makers and the public with a more concrete feel for how masks impact the dynamics of virus spread, we are making an interactive visualization of the ABM simulation available online at http://dek.ai/masks4all. We recommend immediate mask wearing recommendations, official guidelines for correct use, and awareness campaigns to shift masking mindsets away from pure selfprotection, towards aspirational goals of responsibly protecting one’s community


Doctor wears 6 masks to show it does not reduce oxygen saturation


Wearing a mask could cut your risk of coronavirus infection by 65 percent UC Davis Health experts say new research suggests masks not only limit infected individuals from spreading the virus, but also protect the wearer.

Two UC Davis Health experts said a range of new research on face coverings shows the risk of coronavirus infection can be reduced by 65 percent for the person wearing the mask.

Researchers said wearing masks is important in stopping the transmission of the virus, as about 30 percent of infections are caused by people who are asymptomatic and unaware they have COVID-19.

The CDC recommends the use of masks or cloth facial coverings when it is not possible to stay at least 6 feet away from others.


The faster a country required masks, the fewer coronavirus deaths it had: study

Some countries have been devastated by the novel coronavirus, and others have escaped lightly.

Why the extreme differences? The main one is that countries that quickly resorted to widespread mask-wearing had far lower death rates and shorter outbreaks, a new study argues.

The authors looked at coronavirus death rates in 198 countries, trying to see why some had painfully high death rates and others very low.

“What we found was that of the big variables that you can control which influence mortality, one was wearing masks,” says Christopher Leffler of Virginia Commonwealth University, one of the study’s authors.


Face Masks for the General Public

Face masks could offer an important tool for contributing to the management of community transmission of Covid19 within the general population. Evidence supporting their potential effectiveness comes from analysis of: (1) the incidence of asymptomatic and pre-symptomatic transmission; (2) the role of respiratory droplets in transmission, which can travel as far as 1-2 meters; and (3) studies of the use of homemade and surgical masks to reduce droplet spread. Our analysis suggests that their use could reduce onward transmission by asymptomatic and pre-symptomatic wearers if widely used in situations where physical distancing is not possible or predictable, contrasting to the standard use of masks for the protection of wearers. If correctly used on this basis, face masks, including homemade cloth masks, can contribute to reducing viral transmission.


Physical distancing of 1 m or more was associated with a much lower risk of infection, as was use of face masks...

Physical distancing of 1 m or more was associated with a much lower risk of infection, as was use of face masks (including N95 respirators or similar and surgical or similar masks [eg, 12–16-layer cotton or gauze masks]) and eye protection (eg, goggles or face shields). Added benefits are likely with even larger physical distances (eg, 2 m or more based on modelling) and might be present with N95 or similar respirators versus medical masks or similar.


Interactive Agent-Based Model Visualization for COVID-19 Masking

Watch this tutorial video and then play with this masksim simulator yourself — we're making an interactive version of this agent-based model available here for you to try experimenting with our new individual agent-based model, and see what different masking policies do. You'll see how much small accidents can affect the spread of infections as we've made each run completely randomized. Try many runs if you want to see the statistical tendencies under different masking policies.




2020 Chu: Physical distancing, face masks, and eye protection to prevent person-to-person transmission of SARS-CoV-2 and COVID-19: a systematic review and meta-analysis
https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)31142-9/fulltext


2020 Howard: Face Masks Against COVID-19: An Evidence Review
https://web.archive.org/web/20200426222831/https://www.preprints.org/manuscript/202004.0203/v1


vf: If 80% of Americans Wore Masks, COVID-19 Infections Would Plummet, New Study Says
https://www.vanityfair.com/news/2020/05/masks-covid-19-infections-would-plummet-new-study-says


2020 Kai: Universal Masking is Urgent in the COVID-19 Pandemic: SEIR and Agent Based Models, Empirical Validation, Policy Recommendations
https://arxiv.org/pdf/2004.13553.pdf


6masks: Doctor wears 6 masks to show it does not reduce oxygen saturation
https://www.facebook.com/watch/?v=325670641786680


UC Davis: Wearing a mask could cut your risk of coronavirus infection by 65 percent UC Davis Health experts say new research suggests masks not only limit infected individuals from spreading the virus, but also protect the wearer.
https://thehill.com/changing-america/well-being/prevention-cures/506651-wearing-a-mask-could-cut-your-risk-of


earlier: The faster a country required masks, the fewer coronavirus deaths it had: study
https://globalnews.ca/news/7075024/mask-wearing-fewer-coronavirus-deaths


evidence: Face Masks for the General Public
https://rs-delve.github.io/reports/2020/05/04/face-masks-for-the-general-public.html


lancet: Physical distancing of 1 m or more was associated with a much lower risk of infection, as was use of face masks...
https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)31142-9/fulltext


simulator: Interactive Agent-Based Model Visualization for COVID-19 Masking
http://dek.ai/masksim/