Re the 1918 Pandemic there was a lot of unintentional social distancing with few cars, few roads and thoroughfares, lots of farms and relatively small population compared with today.
Apparently the Spanish Flu (nothing to do with Spain) was mostly spread by returning troops huddled up in troop ships and in huge army camps all over Europe waiting to return home, plus with poor diets and conditions immune systems were affected.
And all the time spent elbow to elbow bleeding all over each other in the trenches...
