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Masks really do lower the risk of serious COVID-19 infections and may even build herd immunity

Some people who refuse to wear masks seem to have the attitude: “What’s in it for me?”

It comes from the well-supported argument that wearing a mask benefits other people by inhibiting the spread of the coronavirus, but probably provides little protection for the wearer.

The result is a mutually-elevated protection stand-off: I wear a mask so you don’t get sick; you wear a mask and I won’t get sick.

However, the evidence is mounting that masks benefit people who wear them by cutting down the dose of the virus that they are exposed to.

How does that work?

The number of viral droplets that seep through the gaps where the mask doesn’t fit tightly is fewer than if you’d copped a sneeze full in the face.

The result tends to be a mild case of COVID-19 or one that is asymptomatic, and therefore one that causes no personal bother.

A new study adds weight to that argument – but it goes further.

Wearing masks isn’t just protecting others. It may help protect you too. Photo: Getty

If the mass wearing of masks leads to an overall reduction in serious illness – and a hefty uptick in asymptomatic cases (not quite the same thing) – then we should also see a lift in population immunity.

As the authors write: “Asymptomatic infections may be harmful for spread but could actually be beneficial if they lead to higher rates of exposure.

“Exposing society to SARS-CoV-2 without the unacceptable consequences of severe illness with public masking could lead to greater community-level immunity and slower spread as we await a vaccine.”

It’s all about viral load

In April, as The New Daily reported, health experts were baffled so many young doctors and nurses were becoming seriously ill, even dying from the coronavirus – a new disease that overwhelmingly impacted older people.

One of the first healthcare workers to die was Li Wenliang, the doctor in Wuhan who raised the flag on the coronavirus outbreak, only to be harassed by police for his trouble.

Dr Li, 34, died after weeks spent treating seriously-ill patients.

Dr Peter Hotez, professor and dean of the National School of Tropical Medicine at Baylor College of Medicine, in an interview with CNN, hazarded a guess: “Maybe it’s due to a higher dose of virus they’re receiving. We don’t really know. It’ll take time to study.”

This idea was supported by Dr Sarah Caddy, Clinical Research Fellow in Viral Immunology and Veterinary Surgeon, University of Cambridge.

In a piece at The Conversation she wrote: it’s known that for some diseases “the dose of virus a person is exposed to will directly correlate with how severe the disease is”.

Joshua D. Rabinowitz, a professor of chemistry and genomics at Princeton, and Caroline R. Bartman, a Princeton research fellow, co-authored a piece in The New York Times.

“Is it possible that Dr Li died because as a doctor who spent a lot of time around severely ill COVID-19 patients, he was infected with such a high dose?” they wrote.

“After all, though he was one of the first young healthcare workers to die after being exposed up close and frequently to the virus, he was unfortunately not the last.

“The importance of viral dose is being overlooked in discussions of the coronavirus.”

In a podcast interview, Professor Peter Doherty told The New Daily that doctors working at close quarters with patients in intensive care were repeatedly exposed to the virus and eventually sick with it.

The bottom line

For regular folk, out and about, or even in a closed environment with other people, wearing a mask will significantly reduce the dose of virus entering their bodies.

The body then makes an immunity response that is able to hold down the low-dose infection. The result is either a mild or asymptomatic illness.

At a high enough population number, we could see a herd immunity that may not be permanent, but could hold in place long enough until a vaccination is successfully deployed.

The authors of the new study argue: “This perspective outlines a unique angle on why universal public masking during the COVID-19 pandemic should be one of the most important pillars of disease control.”

Put it on, keep it on.

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