"The number of coronavirus disease 2019 (COVID-19) cases in Austria dropped from 90 to 10 cases per one million people, two weeks after the government required everyone to wear a face mask on April 6."
Austria Has 90% Drop in Coronavirus Cases After Requiring People to Wear Face Masks
The Science Times, April 21, 2020
Universal Masking is Urgent in the COVID-19 Pandemic: SEIR and Agent Based Models, Empirical Validation, Policy Recommendations
Kai, De & Goldstein, Guy-Philippe & Morgunov, Alexey & Nangalia, Vishal & Rotkirch, Anna. (2020). Universal Masking is Urgent in the COVID-19 Pandemic: SEIR and Agent Based Models, Empirical Validation, Policy Recommendations. 10.13140/RG.2.2.21662.08001.
"...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..."
Movement for population-wide use of homemade masks as critical protective equipment against COVID-19.
Theresa Tam Offers New Advice: Wear a Non-Medical Face Mask when Shopping or Using Public Transit
Globe and Mail, April 6, 2020
"Canada’s Chief Public Health Officer has new advice for Canadians: Wear a face mask to help cut down the spread of the novel coronavirus when you are in situations where you can’t always maintain proper physical distance from others."
Image: Adrian Wyld/The Canadian Press
Testing the Efficacy of Homemade Masks: Would They Protect in an Influenza Pandemic?
Anna Davies, KatyAnne Thompson, Karthika Giri, George Kafatos, Jimmy Walker and Allan Bennett Testing the Efficacy of Homemade Masks: Would They Protect in an Influenza Pandemic?. Disaster Medicine and Public Health Preparedness, Available on CJO 2013 doi:10.1017/dmp.2013.43
Country-wide Mortality from the Novel Coronavirus (COVID-19) Pandemic and Notes Regarding Mask Usage by the Public
"Numerous countries which have maintained their mortality asymptote orders of magnitude below that of the hardest-hit regions have widespread adoption of masks by the public."
Leffler, Christopher & Ing, Edsel & Mckeown, Craig & Pratt, Dennis & Grzybowski, Andrzej. (2020). Country-wide Mortality from the Novel Coronavirus (COVID-19) Pandemic and Notes Regarding Mask Usage by the Public. 10.13140/RG.2.2.36006.27200.