Since April, health experts have urged people to wear face coverings to protect others from COVID-19. It turns out masks don’t only help curb community spread; masks also reduce how sick you get from COVID-19 if you get infected.
According to Dr. Monica Gandhi, an infectious disease specialist at UC-San Francisco, face masks may not fully protect you from getting COVID-19, but they block at least some of the infected droplets you inhale.
“The more virus you get into your body, the more sick you are likely to get,” she said in a news release by UCSF.
In a paper published in the Journal of General Internal Medicine, Gandhi proposes that masks can lead to milder or asymptomatic infections because they cut down on the dose of virus that people take into their bodies.
“Masks can prevent many infections altogether, as was seen in health care workers when we moved to universal masking. We’re also saying that masks, which filter out a majority of viral particles, can lead to a less severe infection if you do get one,” Gandhi said. “If you get infected, but have no symptoms—that’s the best way you can ever get a virus.”
Said Dr. Craig Jenne, an infectious disease specialist at the University of Calgary, via Global News: “There’s so much difference in the severity of coronavirus in the public, and this may explain some of it. There will be genetics and everything else, but this might contribute to some of the reasons why some people don’t even know they’re sick or are mildly ill, and others are unfortunately hospitalized.”
How masks can reduce the coronavirus symptoms
The concept of a viral dose, called inoculum, is not a new concept, according to Gandhi. In 16th-century China, the first vaccines worked by exposing people to small quantities of smallpox virus to cause a mild reaction that led to immunity.
Gandhi and her colleagues studied a variety of examples where masks in a community reduced the coronavirus’ potency and led to milder symptoms. For example, when COVID-19 spread aboard the Diamond Princess cruise ship in February, just 18% of the 634 people infected were asymptomatic. But in March, when COVID-19 spread on an Argentinean cruise ship, 81% of the 128 people infected were asymptomatic. The main difference was that the Argentinean ship provided surgical masks to passengers and the Diamond Princess ship did not.
Additionally, two recent outbreaks in food processing plants led to a 95% asymptomatic infection rate. At both plants, workers were required to wear face coverings.
According to the paper, the way deaths dropped in countries that embraced masks is another indicator that masks reduce severity in illness. Countries already accustomed to wearing masks during public health crises—like Japan, Hong Kong, Taiwan, Thailand, South Korea, and Singapore—saw a decrease in the mortality rate during subsequent outbreaks.
“This group showed that, if 80% of the population wears a moderately effective mask, nearly half of the projected deaths over the next two months could be prevented,” the paper says.
In a study released in September, researchers showed that U.S. citizens actually have been wearing masks more often in the previous two months.
Gandhi and her colleagues believe that until a vaccine is readily available, masks could lead to herd immunity in the communities.
“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,” Gandhi wrote in the paper.
Because of these new perceived benefits of face coverings, Gandhi told Healthline that she supports the idea of a national mask mandate.
“We messaged that mask wearing will protect other people, and that did not seem to convince our country as much as we would have hoped,” Gandhi said. “If you think something’s going to help you or your family, you are going to do it more than if you think you’re helping others.”
Read more on coronavirus face coverings:
- Are there any valid medical reasons to not wear a mask?
- Wearing a face shield might not be as effective as you think to stop the coronavirus
- Not all masks are effective against COVID-19: Here’s a ranking of how safe they are
- Yes, you should STILL be wearing a face mask during the pandemic
- Pandemic experts say we may live with masks for years
- How face masks are affecting the deaf and hard of hearing community
- What’s the difference between an N95, an N99, and a R95 face mask?