２重マスクが有効だ、と。

CDC study recommends double masking to reduce Covid-19 exposure https://t.co/Lz5OF2c7Eb

— The Guardian (@guardian) February 10, 2021

顔に密着させた２重マスクか。

Recent forecasts have also begun to take universal masking into account. If 95% of people wore masks in public, forecasters at the Institute for Health Metrics and Evaluation believe more than 116,000 lives could be saved by 1 June, compared with the institute’s “worst-case” scenario, in which 702,000 people could die from Covid-19.

欧米のマスクなんて不要説から１８０度転換だね。