Study suggests mask-wearing can lessen COVID-19 severity

Posted at 2:46 PM, Sep 22, 2020

CHICAGO, Ill. – A study published this month suggests that by lessening the amount of virus you take in by putting on a mask, you may also lessen the likelihood of getting severely sick if you contract COVID-19.

As the race to a safe and effective coronavirus vaccine heats up, new research about masks is changing the narrative on their importance.

Last week, CDC Director Dr. Robert Redfield called face masks the most “powerful public health tool we have.”

“I might even go so far as to say that this face mask is more guaranteed to protect me against COVID than when I take a COVID vaccine,” said Dr. Redfield.

It was a stark change from CDC messaging early on in the pandemic that face coverings would most likely only protect those around you.

“That was because there was a lot of data at that time that you can shed the virus at high rates from your nose and mouth even when you feel well,” said Dr. Monica Gandhi, an infectious disease doctor and professor of medicine at the University of California – San Francisco.

She co-authored newly published research in the New England Journal of Medicine that theorizes that not only do masks protect the wearer but they may even reduce the severity of the coronavirus when someone gets infected.

“We realized that we should be messaging more strongly masks protect you as the wearer and protects others,” said Dr. Gandhi.

It theoretically works much like the early days of vaccines that used small amounts of viruses to illicit an immune response in the body. So, by wearing a mask, you are only exposed to lesser amounts of the virus, if any, potentially building up a sort of immunity.

“The more virus you get inside, the sicker you are, the less virus you have, the less sick you are. This is called a dose response and it's true of many infections,” said Dr. Emily Landon, an epidemiologist and infectious disease specialist at University of Chicago Medicine.

Gandhi says the theory has already been studied and proven in animals.

“There was a hamster study that looked at the COVID-19 virus and the more that the hamsters were given, the more sick they got,” she said.

Dr. Gandhi says it could also explain the why according to the CDC, 40% of coronavirus patients are asymptomatic.

“Countries that mask well have lower rates of severe illness than countries that don't mask well. So, putting it all together, this is our hypothesis.”

And while the research is still theoretical, if it bears out, experts say universal mask-wearing could drive up the proportion of people who get less sick from the virus if they do contract it.