Wear a mask to protect yourself

All referenced hyperlinked below for personal perusal and verification. CDC

https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/cloth-face-cover-guidance.html

Masks reduce the spray of droplets when worn over the nose and mouth

Prevent people who have COVID-19 from spreading virus to others

Respiratory virus shedding in exhaled breath and efficacy of face masks (Nature Medicine)

https://www.nature.com/articles/s41591-020-0843-2

Aerosol transmission is a potential mode of transmission for coronaviruses as well as influenza viruses and rhinoviruses

Universal use of face masks for success against COVID-19: evidence and implications for prevention policies (European Respiratory Journal)

https://erj.ersjournals.com/content/55/6/2001260

Cloth masks are a simple, economic and sustainable alternative to surgical masks as a means of source control of SARS-CoV-2 in the general community

Mask wearers are dramatically less likely to get a severe case of Covid-19

https://www.inverse.com/mind-body/masks-breathing-in-less-coronavirus-means-you-get-less-sick

Professor Monica Gandhi, San Francisco General Hospital.

No mask is perfect

Wearing one might not prevent you from getting infected

But it might be the difference between a case of Covid-19 that sends you to the hospital and a case so mild you don’t even realize you’re infected.

Masks Do More Than Protect Others During COVID-19: Reducing the Inoculum of SARS-CoV-2 to Protect the Wearer (Journal of General Internal Medicine)

https://link.springer.com/article/10.1007/s11606-020-06067-8

Universal masking reduces the “inoculum”

Leading to more mild and asymptomatic infection manifestations

Masks, depending on type, filter out the majority of viral particles, but not all

Viral inoculum and severity of disease (LD50)

Rising rates of asymptomatic infection with population-level masking

Increased with mask wearing, decreased where few masks are worn

So, more asymptomatic infections

Greater community-level immunity and slower spread
Cloth Masks May Prevent Transmission of COVID-19: An Evidence-Based, Risk-Based Approach (Annals of Internal Medicine)

https://www.acpjournals.org/doi/10.7326/M20-2567
The point is not that some particles can penetrate but that some particles are stopped

Every virus-laden particle retained in a mask is not available to hang in the air as an aerosol or fall to a surface to be later picked up by touch.

Cloth can block droplets and aerosols, and layers add efficiency.

Immunity and immunopathology to viruses: what decides the outcome? (Nature, Reviews Immunology)

https://www.nature.com/articles/nri2802

The outcome of host–viral interactions depend on

Dose and route of infection

Viral virulence properties

Several host factors that mainly involve innate and adaptive immunity

If the exposure dose is very high, the immune response can become overwhelmed.

If the initial dose of the virus is small, the immune system is able to contain the virus with less drastic measures.

If this happens, fewer symptoms, if any

A simple method of estimating fifty per cent end points, (American Journal of Hygiene, 1938)

https://academic.oup.com/aje/article-abstract/27/3/493/99616?redirectedFrom=fulltext

Viral dose being related to disease severity

Validation of the Wild-type Influenza A Human Challenge Model H1N1pdMIST: An A(H1N1)pdm09 Dose-Finding Investigational New Drug Study (Clinical Infectious Diseases)

https://academic.oup.com/cid/article/60/5/693/291415

Clinical symptoms of influenza occurred at all doses (Table 1), but were most prevalent at 106 and 107 TCID (tissue culture infectious dose)

Higher viral doses, the more sick people became

Simple Respiratory Protection—Evaluation of the Filtration Performance of Cloth Masks and Common Fabric Materials Against 20–1000 nm Size Particles, (The Annals of Occupational Hygiene)

https://academic.oup.com/annweh/article/54/7/789/202744

Masks increase the rate of asymptomatic cases, (Annals of Internal Medicine)

https://www.cdc.gov/coronavirus/2019-ncov/hcp/planning-scenarios.html

https://theconversation.com/can-people-spread-the-coronavirus-if-they-dont-have-symptoms-5-questions-answered-about-asymptomatic-covid-19-140531

https://www.acpjournals.org/doi/10.7326/M20-3012

COVID-19: in the footsteps of Ernest Shackleton, (MBJ, Thorax)

https://thorax.bmj.com/content/75/8/693

Cases at seafood plant cause spike in Oregon COVID numbers (Pacific Seafoods)

https://apnews.com/4b9d38f206db9ce5267a5898ac24f238

Releases Covid-19 Test Results at Northwest Arkansas Facilities (Tyson)

https://www.tysonfoods.com/news/news-releases/2020/6/tyson-foods-inc-releases-covid-19-test-results-northwest-arkansas

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