Masks May Reduce inhaling Viral Dose: New research paper

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, an infectious disease physician at the University of California, San Francisco. If any virus particles do breach these barriers, she said, the disease might still be milder.

Dr. Gandhi and her colleagues make this argument in a new paper slated to be published in the Journal of General Internal Medicine. Drawing from animal experiments and observations of various events during the pandemic, 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.

Dr. Tsion Firew, an emergency physician at Columbia University who wasn’t involved in the work, 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.”