Beriberi and pellagra are not viral infections but nutritional
deficiencies. I doubt very much the Germans or anyone else had the
knowledge to generate influenza viruses at the time of WWI. I'm not even
sure the virus had been identified and grown by then, though the Spanish
Flu virus was found in pigs in the 20's or 30's (I don't recall which).
The Germans are alleged to have tried to spread flu in the London Subways
but I don't recall when.
--John
