SAN FRANCISCO - New research debunks the idea that masks protect others from coronavirus, but not the wearer.
A report from UCSF, in conjunction with other research hospitals, concludes masks can reduce COVID-19 load enough for the immune system to ward it off.
When mask-wearers are infected, they tend to have no symptoms, mild symptoms, and higher survivability, compared to people who don't wear masks.
"You want to get back to normal life ? Wear a mask," said Dr. Monica Gandhi, one of the study's co-authors.
Gandhi is a professor of medicine at UCSF and associate division chief of the infectious disease program at San Francisco General Hospital.
She wears a surgical isolation mask all day in clinic, and a stretchy fabric mask when she's not working.
"I think coronavirus would collapse if we all wore a mask consistently, absolutely," declared Gandhi.
Gandhi admits masks got a rough launch among Americans.
Shortages of medical equipment and mixed messages led to confusion and a lack of commitment.
As a result, Gandhi says, it's no accident the U.S. is now the epicenter of the pandemic.
"Hitting people with lots and lots of virus inundates them, it's the dose," she explained.
The theory of viral inoculum goes back decades, to early research among lab mice.
"When you give the animal a bigger dose of a virus they get more sick," said Gandhi.
And in limited human testing ?
"Humans who got more of a dose of influenza A got more sick than humans who got less of a dose," she confirmed.
During the current pandemic, hamsters were tested.
"They didn't actually put masks on a hamster, that would be really hard to do," smiled Gandhi.
"But they actually put a mask all over the cage and then exposed them to Covid-19"
Researchers found the hamsters in the masked cage were less likely to contract the virus.
"Also if they did get it, they really didn't get sick," noted Gandhi.
Evidence has emerged on cruise ships too.
The outbreak on the Diamond Princess in Japan, before masks were prevalent, ended up with about 4 out of 5 infected passengers actually becoming sick, a high rate.
On an Argentinian cruise ship, where everyone masked-up early, the same ratio were asymptomatic or mildly ill, a remarkably low number.
"It is still a terrible thing to get severe illness and be hospitalized," said Gandhi.
"And there can be long lasting affects, so we should never, never, never allow people to get ill."
When Asian nations were ravaged by the SARS pandemic of 2003, the public became accustomed to masks, and swift compliance during Covid is credited with controlling the spread.
In the Czech Republic, with no history of mask mandates, the population was told to mask on March 23rd, and by May 11, shelter and mask orders were lifted, and normalcy resumed, with only 360 deaths in the entire country.
"Putting that all together we are convinced that masks protect you as well, and it is the right strategy to share with people," said Gandhi.
The doctor says any mask will do, as long as it is snug enough that it does not sag, and comfortable enough to want to wear it.
She finds it ridiculous large sections of the U.S. are debating masks, and even going to court over them.
And she regrets that notions of personal freedom got mixed into public health.
"I'm really horrified because this is scientific, " said Gandhi.
"Everyone is miserable, we all want to get through the pandemic faster, so we all have to wear a mask."
The CDC advised cloth facial coverings on April 3, but President Trump and other conservative politicians downplayed their value.
"The way Trump put it was 'yeah, this is voluntary, I may or may not do it,'" said Gandhi.
"And he's only worn a mask in public once and that was just a few days ago."
She believes leaders have a responsibility to model mask-wearing, but if they don't, the public should realize masks are genuine protection, and go beyond a civic duty.
"People are more likely to do things when they know it protects them as well as protects others so it's a very strong and important message to get out."
The mask phenomenon also explains why so many health care workers were sickened at first, but less so now.
And cities such as New York began bent their curve and saw death rates plummet when mask-wearing took hold.
Masks, however, remain controversial, particularly in the South.
In Georgia, the Governor is trying to invalidate local mask mandates in several cities.
"You get used to a mask, and we don't have to do it forever," implored Gandhi, "and we'll get through this pandemic if you do it."