"The study by the CDC is interesting because it's one of the first that applies good hard science to understanding masks," said Dr. Robert Citronberg, an infectious disease doctor at Advocate Aurora Health.
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The CDC suggests wearing a cloth mask over a surgical mask or tightening the ear loops on a single surgical mask for a snug fit. The point is not to feel air coming out of the sides.
"This is especially useful for people with smaller faces because the standard size masks are almost too big for people with smaller faces," Citronberg said.
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Both methods are suggestions only. The CDC is not changing its mask guidelines.
Chicago Health Commissioner Dr. Allison Arwady said she plans to review the CDC study before making decisions on mask changes.
"The most important thing by far is that people actually wear the masks and do the distancing, wash hands," Dr. Arwady said.
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Guidance on masks has evolved. At the beginning of the pandemic, masks were not recommended for the masses.
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"A year ago, we really underestimated the amount of transmission that occurs with people without symptoms," Dr. Citronberg said. "We thought, just isolate people with symptoms and don't worry about everyone else."
Masks came into play as the virus spread through asymptomatic people. And as vaccination rates rise, doctors say masks must still be worn because for now, it is not known if vaccines prevent the transmission of the disease.
Although, that could change in the future as more is learned about the vaccines.