Wearing two face masks or adjusting a mask to fit more snuggly can better help protect against COVID-19 and its highly transmissible variants, the Centers for Disease Control and Prevention advised in new guidance out Wednesday.
Why it matters: Modeling shows the B.1.1.7 variant from the U.K. could become the dominant strain in the U.S. by the end of March, said Anthony Fauci, President Biden's chief medical adviser, on Wednesday.
"We should not despair with that because there are things that we can do to prevent that. It is not outside of our power to do that," Fauci said in a COVID response meeting.
- "For example, the vaccines that we are using clearly are effective against this. We know that from in vitro correlate studies as well as for vaccines that are other candidates," he added.
The state of play: Wearing a cloth mask over a surgical mask, knotting the ear loops of a surgical mask and tucking in extra material, or wearing a "mask fitter" device for a closer fit are all effective ways to reduce transmission, the study says.
- Both methods reduced exposure to potentially infectious aerosols by more than 95% in a laboratory experiment using dummies.
- Mask-wearing is to be used along with social distancing, avoiding crowds and poorly ventilated indoor spaces, and practicing frequent handwashing, Fauci said.
The big picture: The study comes as public health experts urge people to upgrade their masks to better protect against COVID-19 transmission while they wait for the vaccine to become more available.
- Another CDC study released earlier this month shows the mask mandates work in reducing hospitalization rates.
- As of Feb. 2, the Biden administration has required masks on planes, buses, trains, and other forms of public transportation traveling into, within or out of the United States and in transportation centers like airports and stations.
