Pandemic science, Wear a mask to protect yourself

All referenced hyperlinked below for personal perusal and verification. CDC

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)

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)

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

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)

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)

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)

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)

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)

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)

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

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

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

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

[davidcrawford]

What a difference a few year makes! Respect for realising your mistake Dr. Campbell.

[spex]

I came across a PPE expert who has spent his life trying to protect workers, and he says if you can pass a hair under your mask anywhere, the pathogen is 1000 times smaller. A mask he says wouldn't feature on the pathogen protective PPE list as they don't work, and I'd agree.

[ayrendelport]

As a person who had Covid-19 and was suppose to get very sick, since my age, my Asthma previous Cancer, and more, I was fortunate not to get severe, believe it was because I am religiously wearing a mask and visor, and yes got the virus thanks to a person who was not wearing a mask, knowing her partner is sick and might have the virus, her partner, in the end, succumbed to this horrible virus sadly, while I can sit here and agree with you.

[eriknystrom]

Thank you for the info! I’m a healthy 73 yo man. I’ve been using homemade masks (made from vacuum cleaner bags) since the beginning of the pandemic in Sweden, believing that it would give me at least some protection from getting infected even if it’s not perfect. I only use them when going into a store or using public transportation and so far I didn’t have any signs of infection. So I’ll continue with my mask habits until there is a vaccine. Note that very few people in Sweden are wearing masks. Anyhow, numbers of hospitalizations and deaths used to be very high, but are now very low in Sweden .

[babysisdolls]

i work in healthcare...mask wearing ..this was first time ever i made it thru allergy & flu season without symptoms or taking medication.

[michaelroland]

I wish the UK government would give talks of this quality, thank you Dr. John.

[ossie]

My sister has made hundreds of masks for family, friends, and schools. There is a pocket in the mask and I add a coffee filter in the pocket for an extra layer. Thank you for all your work Dr. Campbell!!!

[mirandayeoh]

Yes, I agree. I have been wearing masks since February. I bought disposable masks and sewed several cloth masks. Cloth masks are better for our environment. Thanks.

[debicaldwell]

Chris Martinson from Peak Prosperity discussed mask wearing affecting the inoculum months ago. It made sense to me! I am glad to see it validated. Thank you, Dr. Campbell. You are a treasure.

[JayUnarmed]

I was born without arms (do everything with my feet) and I am able to put a mask on myself, anyone that has an excuse not to wear one I'd like to see them justify that to me.

[laurenjacobsen]

Completely makes sense. Shared this with my friends. Oregon, USA

[Larissa-ofqt]

Your videos have saved so many lives already Mr. Campbell. THANK YOU from the bottom of my heart. No one has contributed educating/informing the public more than you do since jan regarding this pandemic. You even corrected so many mistakes of WHO, and all other so called health organisations and gov's misleading and untrue informations and each time you happened to be spot on with your knowledge and analysis .

[viedeprimes]

Just been to a shopping Centre where most people are wearing masks, however, about half (if not more than half) are wearing masks only covering their mouth. So there is more mask wearing compared to last month but not covering up appropriately.

[TheAnnietwentythree]

I work in retail, I wear a mask 😷 always as I’m now seeing that more and more customers not even bothering to wear a mask whilst shopping. 🙁

[jennamartin-payne]

I was so worried at the beginning of this and I found your videos. Throughout the last few months you have provided a peace of mind I haven't found elsewhere. Knowing the situation accurately has helped us to make decisions to keep our clinically vulnerable family members safe. We've even given you the title 'Uncle John' in this house! Thank you so much for all your help, from us and our little people :)

[lynnmckenna]

N95 masks should be available to the general population. In USA, where I live, we produce nuclear weapons but somehow cannot produce N95 face masks.

[anonymouse]

Thank you for making things easy to understand for everyone! Please continue to educate us.

[Pierremontquaker]

There is something strangely comforting with all the underlining and ticking.

[georgejohnson]

Dear Dr John,

I watch your videos as soon as I know they have been uploaded. Sometimes, I leave bit early, once I get the picture, but almost always get to the end, and find myself knowing more ...

I have been using so many of your methods and advice, like opening the windows at work to get a flow of fresh air. Of course this will get more difficult in the Autumn and Winter as not everyone is as immune to cold as I am!

As for this film, and entirely without any qualifications in the subject at all, it seemed obvious to me that the severity of inoculation would be likely to have an effect on how seriously ill you might get. You confirm this today, and that is gratifying. For once I read the comments [at least so far], and am horrified that people who cannot listen with an open mind would even tune in to your sane, quietly spoken lectures.

As for the reactions of those who claim wearing a face mask is an affront to their freedom, this video should cause pause for thought. But it will not ...

You can lead a horse to water, but you cannot make it drink. Unfortunately there are people who will never take the precautionary approach. Indeed there are people who are offended by the merest suggestion that their own firm opinion might not quite be correct.

All we can do as individuals is do the best we can, and it seems to me that in the current situation wearing a face mask in public spaces is the least we can do. It will not go on forever, and if by wearing a mask, I become less ill, or indeed save a vulnerable older or otherwise weakened with co-morbidities individual from getting seriously ill or dying, then it its the very least I can do. For those who choose a different course, then I simply say that there is nothing that more you or I can do.

Best wishes from George

[steklf]

Science experiments with Dr Campbell, I love it