it seems most ppl in 1918-19 died of bacterial pneumonia through sustained mask wearing & the vaccine itself. the casualties were mostly 20-40yo, the generation who had spent 4 years in mudfilled trenches in all weathers with little nutrition. a strong wind would have blown them away; their minds were filled 100% with horror and death. it seems doubtful any virus actually physically passes from one person to another, rather the seed is planted through fear into a mind which then attempts to replucate symptoms inside the body, triggering the body's ability to form viruses within.
It is reported that the only people able to assist during the spanish influenza were people that had not received the small pox vaccine