The 1918 “Spanish” flu pandemic also killed mostly young adults. That pandemic was one of the worst in all of human history, but is nearly forgotten now. Woodrow Wilson severely mishandled the epidemic because of his misadventure in getting us involved in what was a European war.
A very good explanation of the “Spanish” flu can be found here:
https://www.youtube.com/watch?v=sE0-WWqhFls&t=186s&frags=pl%2Cwn
The group that produced this is also doing a YouTube week-by-week history of WWII. Their latest is for the week of June 1, 1940. Indie Nidell, the narrator also did a week-by-week history of the Great War which ended in Nov. 2018
That’s true. Flu is typically most dangerous to the very young, the very old, and people with chronic illnesses.
The 1918 pandemic was different. It affected mostly young, healthy people. I watched a program about it not long ago. There were stories of a young person going out to work one day, and that same person’s body being carried out the next day.
My maternal grandparents lost one of their children at 18 months old. Her death certificate states that she died from pneumonia, as a complication of the flu. I believe my grandfather also had a brother who died, a young man with a family.
I read that the first known cases of the 1918 epidemic were in Kansas, of all places.