People wearing face coverings will take in fewer coronavirus particles, evidence suggests, making disease less severe.
Researchers have long known that masks can prevent people from spreading airway germs to others — findings that have driven much of the conversation around these crucial accessories during the coronavirus pandemic.
But now, as cases continue to rise across the country, experts are pointing to an array of evidence suggesting that masks also protect the people wearing them, lessening the severity of symptoms, or in some instances, staving off infection entirely. Different kinds of masks “block virus to a different degree, but they all block the virus from getting in,” said Dr. Monica Gandhi
Dr. Gandhi and her colleagues make this argument in a new paper slated to be published in the Journal of General Internal Medicine.
they contend that people wearing face coverings will take in fewer coronavirus particles, making it easier for their immune systems to bring any interlopers to heel.
cautioned that the links between masking and milder disease haven’t yet been proved as cause and effect. Even so, the new paper “reiterates what we say about masks,” she said. “It’s not just a selfless act.”
a team of researchers in China tried something similar in hamsters:
They housed coronavirus-infected and healthy animals in adjoining cages, some of which were separated by buffers made of surgical masks. Many of the healthy hamsters behind the partitions never got infected. And the unlucky animals who did got less sick than their “maskless” neighbors.
Some indirect data has been accumulating from people as well. Researchers have tentatively estimated that about 40 percent of coronavirus infections do not produce any symptoms.
Wearing a face covering doesn’t make people impervious to infection, but these trends of asymptomatic cases could suggest that masks lead to milder disease, potentially reducing hospitalizations and deaths.
To me, it seems like getting a “low dose of the virus” is similar to getting a vaccination. Our body’s immune system can handle a few of these virus particles and thereby learn and get set up to fight the next invasion instead of being caught flat-footed and unprepared.
Some independent experts say the paper is a welcome update, given the pervasive idea that wearing a mask is a mostly altruistic act.
“It’s been a real deficiency in the messaging about masking to say that it only protects the other,” said Charles Haas, an environmental engineer and expert in risk assessment at Drexel University.
“From the get go, that never made sense scientifically.”
That’s exactly what I’ve been thinking all along, it seems so obvious.
Without any special knowledge or a high IQ, common sense would tell us that a barrier that prevents your exhalations from spewing out towards others would also prevent other people’s exhalations from spewing directly onto you.
Even in the United States, the slow upward tick in mask-wearing has coincided with what appears to be a more modest death rate, compared to the surge that occurred after the virus first made landfall in North America.
The idea that face coverings can curb disease severity, although not yet proven, “makes complete sense,” said Linsey Marr, an expert in virus transmission at Virginia Tech.
But based on a wealth of past evidence and recent observations, the amount that’s filtered out is probably high — perhaps 50 percent or more of the larger aerosols being sent in both directions, Dr. Marr said. Certain coverings, like N95 respirators, will do better than others, but even looser-fitting cloths can waylay some viral particles.
While there’s good evidence that masks reduce the spread of viruses within a population, it’s much harder to nail down how face coverings influence symptoms, Dr. Leung said, in part “because of the difficulty in conducting those studies.”
Even people who don’t have symptoms can spray the virus into their environment when they sneeze, cough, sing, speak or even breathe. And those who fall ill may be at their most contagious in the days before the first signs of sickness appear.
To tame this pandemic, people should act as if they’ve been infected, “even if you feel right as rain,” Dr. Gandhi said.
Masks alone aren’t a substitute for other public health measures like physical distancing and good hygiene. But unlike sustained lockdowns that keep people apart, shielding our faces is easier and more sustainable, Dr. Gandhi said.