Please ensure Javascript is enabled for purposes of website accessibility
Study: Wearing a Mask Protects You From Severe COVID-19 Symptoms
TLBBHMAP3-U010ALB5ANM-348f959abae2-512-300x300-1
By Jim Jakobs, Digital Producer
Published 5 years ago on
July 15, 2020

Share

Masks appears to do more than protect others during COVID-19. They protect the mask user, too.

That’s the finding of a report written by infectious disease experts that’ll publish soon in the Journal of Internal Medicine.

GV Wire℠ received an advance copy of the report from Dr. Monica Gandhi, one of the study’s co-authors. Gandhi is a professor of medicine at UC San Francisco and associate division chief of the infectious diseases program at San Francisco General Hospital.

Lower Dose of Virus if Wearing Mask

“Masks work,” Ghandi said in an email. “They protect others but they also protect you. You will get in a lower dose of virus if you wear a mask and are exposed to COVID-19 and are very likely to have mild or no symptoms.”

“You will get in a lower dose of virus if you wear a mask and are exposed to COVID-19 and are very likely to have mild or no symptoms.”Dr. Monica Gandhi, UC San Francisco

Depending on how robust the person’s immune system is, a smaller exposure appears to correlate with milder cases of COVID-19. It’s probably because with a smaller amount of virus to deal with, the body’s immune system has a better chance of mounting a defense, the paper’s authors suggest.

It also appears people who wear masks but contract the disease are much more likely to be asymptomatic, meaning they have COVID-19 but no symptoms.

Gandhi Facial Masking and the Viral Inoculum COVID 19 JGIM 7 9 20 (Text)

Theory of Viral Inoculum

Researchers focused on the theory that mask wearers receive less airborne COVID-19 droplets, and therefore give their immune systems a better chance of fighting off the droplets that get through. It’s what the writers call the theory of viral inoculum.

The theory that exposure to a lower dose of any virus (whether respiratory, gastrointestinal, or sexually-transmitted) can make subsequent illness far less likely to be severe has been discussed for some time.

The researchers’ goal was to deliver one of the first perspectives discussing evidence to support this theory.

Read the Study


Hamsters, Cruise Ships & Food Processing Plant Examples

Studying this theory on humans is not possible because exposing humans to varying levels of COVID-19 is not ethical.

But, a frequently-cited study shows that hamsters are less likely to contract SARS-CoV-2 infection with a surgical mask partition. Those hamsters that did contract COVID-19 with simulated masking had milder manifestations of infection, Ghandi’s report says.

Photo of a helicopter carrying airmen with the 129th Rescue Wing flying over the Grand Princess cruise ship
The study references COVID outbreaks onboard cruise ships. Masks were not widely used on the Diamond Princess (pictured), where only 18% of infected passengers experienced no symptoms. By comparison, all passengers and crew aboard the Ernest Shackleton were issued masks, with 81% of those infected being asymptomatic. (AP File)

One of the earliest estimates of asymptomatic COVID infection was from the COVID-19 outbreak on the Diamond Princess cruise ship. Masks were not provided on the ship and the number of asymptomatic infections was below 20%, the report states.

In a more recent report from a different cruise ship outbreak aboard the Ernest Shackleton, all passengers were issued surgical masks and all staff provided N95 masks after the initial case of COVID-19 on the ship was detected. In that setting with masking, where 128 of 217 passengers and staff eventually tested positive for  COVID-19, the study states that 81% of infected patients remained asymptomatic, compared to 18% on the Diamond Princess.

The authors also referenced a recent outbreak in a seafood processing plant in Oregon where all workers were issued masks each day at work. The rate of asymptomatic infection among the 124 infected was 95%.

Faster Immunity & Slower Spread

The authors write, “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.”

Says Dr. Gandhi: “We can get through this pandemic much more quickly – in the next 6 weeks, estimates say — if we all wear a mask. So do it as this pandemic is miserable!”

Gandhi Facial Masking and the Viral Inoculum COVID 19 JGIM 7 9 20 (Text)

RELATED TOPICS:

DON'T MISS

What Are Fresno Real Estate Experts Predicting for 2025 and Beyond?

DON'T MISS

First California EV Mandates Hit Automakers This Year. Most Are Not Even Close

DON'T MISS

Authorities Seek Help Finding Relatives of Deceased Fresno Man

DON'T MISS

Valley Crime Stoppers’ Most Wanted Person of the Day: Felecia Johnson

DON'T MISS

How in the World Did Fresno End Up on Trump’s Sanctuary Cities List?

DON'T MISS

X Marks the Spot: Bruised Musk Says His Young Son Punched Him

DON'T MISS

PBS Suing Trump Administration Over Defunding, Three Days After NPR Filed Similar Case

DON'T MISS

Loretta Swit, Emmy-winner Who Played Houlihan on Pioneering TV Series ‘M.A.S.H.,’ Has Died at 87

DON'T MISS

San Francisco 49ers Acquire Eagles Edge Rusher Bryce Huff, AP Source Says

DON'T MISS

California Lawmaker Won’t Be Charged After Citation for Suspicion of Impaired Driving

DON'T MISS

California School Awards Dinner at Disneyland Comes With Hefty Price Tag

DON'T MISS

Fresno Police Release Video of Officer-Involved Shooting

UP NEXT

California Lawmaker Won’t Be Charged After Citation for Suspicion of Impaired Driving

UP NEXT

1 in 4 US Children Have Parents With Substance Use Disorder, Study Finds

UP NEXT

Dozens Sickened in Expanding Salmonella Outbreak Linked to Recalled Cucumbers

UP NEXT

Newsom Tussles With Local Officials Over Homelessness

UP NEXT

How Trump’s Vow to Revoke Chinese Student Visas Could Hurt California

UP NEXT

Speaker Johnson Raises Campaign Money in Fresno

UP NEXT

A Program Paying CA Jurors $100 a Day Would End Due to Newsom’s Budget Cuts

UP NEXT

White House Acknowledges Problems in RFK Jr.’s MAHA Report

UP NEXT

‘I’m Really Scared’: Elderly and Disabled Californians Could Lose Medi-Cal Over $2,000 Limit

UP NEXT

Trump Administration Revokes Parole of Mexican Girl Receiving Lifesaving Care in US

X Marks the Spot: Bruised Musk Says His Young Son Punched Him

2 hours ago

PBS Suing Trump Administration Over Defunding, Three Days After NPR Filed Similar Case

2 hours ago

Loretta Swit, Emmy-winner Who Played Houlihan on Pioneering TV Series ‘M.A.S.H.,’ Has Died at 87

3 hours ago

San Francisco 49ers Acquire Eagles Edge Rusher Bryce Huff, AP Source Says

3 hours ago

California Lawmaker Won’t Be Charged After Citation for Suspicion of Impaired Driving

3 hours ago

California School Awards Dinner at Disneyland Comes With Hefty Price Tag

5 hours ago

Fresno Police Release Video of Officer-Involved Shooting

5 hours ago

Hamas Says It Is Still Reviewing a US Proposal for a Gaza Ceasefire

5 hours ago

1 in 4 US Children Have Parents With Substance Use Disorder, Study Finds

5 hours ago

Oreo Maker Mondelez Sues Aldi, Alleging Grocery Chain Copies Its Packaging to Confuse Customers

5 hours ago

Authorities Seek Help Finding Relatives of Deceased Fresno Man

The Fresno County Sheriff-Coroner’s Office is asking for the public’s help in locating family members of a Fresno man who died last month. F...

43 seconds ago

The Fresno County Sheriff-Coroner’s Office is seeking the public’s help to locate the family of Felipe Pech, 68, of Fresno, who died on April 23, 2025. (Fresno County SO)
44 seconds ago

Authorities Seek Help Finding Relatives of Deceased Fresno Man

Felecia Johnson is Valley Crime Stoppers' Most Wanted Person of the Day for May 30, 2025. (Valley Crimes Stoppers)
51 minutes ago

Valley Crime Stoppers’ Most Wanted Person of the Day: Felecia Johnson

1 hour ago

How in the World Did Fresno End Up on Trump’s Sanctuary Cities List?

2 hours ago

X Marks the Spot: Bruised Musk Says His Young Son Punched Him

2 hours ago

PBS Suing Trump Administration Over Defunding, Three Days After NPR Filed Similar Case

3 hours ago

Loretta Swit, Emmy-winner Who Played Houlihan on Pioneering TV Series ‘M.A.S.H.,’ Has Died at 87

3 hours ago

San Francisco 49ers Acquire Eagles Edge Rusher Bryce Huff, AP Source Says

3 hours ago

California Lawmaker Won’t Be Charged After Citation for Suspicion of Impaired Driving

Help continue the work that gets you the news that matters most.

Search

Send this to a friend