Journal of Infectious Diseases, March 1919:
"Since June 1, 1916, gauze masks have been used by the nurses ... No case of scarlet fever has occurred since masks have been worn."
"Since June 1, 1916, gauze masks have been used by the nurses ... No case of scarlet fever has occurred since masks have been worn."
World Health Organization, March 2020:
"There is no specific evidence to suggest that the wearing of masks by the mass population has any potential benefit. In fact, there's some evidence to suggest the opposite."
"There is no specific evidence to suggest that the wearing of masks by the mass population has any potential benefit. In fact, there's some evidence to suggest the opposite."
So, it took 101 years to unlearn the idea that putting a piece of fabric over everybody's nose and mouth just might stop some infectious droplets from traveling freely between people's noses and mouths.
