Wu Lien-teh helped to end the Manchurian plague outbreak of 1910-11 with the use of face masks he had designed made from cotton and gauze, and stopped the disease from reaching other parts of China
Source:
https://www.newscientist.com/article/2270735-wu-lien-teh-face-mask-pioneer-who-helped-defeat-a-plague-epidemic/?utm_campaign=RSS%7CNSNS&utm_source=NSNS&utm_medium=RSS&utm_content=home