The following influenza contagion study was published by the Treasury Department: United States Public Health Service, February, 1921, p. 5 – 41, in which it was concluded that:
“The results of our experiments do not warrant positive conclusions.”
https://quod.lib.umich.edu/cache/3/7/5/3750flu.0016.573/00000011.tif.1.pdf#zoom=75