It's clear from the material I've read that people were aware of the Spanish Flu (sometimes referred to as "La Grippe" in Europe). Given that the flu's transmission was perhaps helped spread by troop movements, I'm wondering whether or not any of the militaries participating in WW1 had any protocol for helping the minimize infection among their troops. Certainly, there are photos of large wards set up among the civilian population in old gymnasiums and the like. Given that the flu attacked younger adults with stronger immune systems, I imagine it would be a big concern for any army.