That was one of the big problems/mysteries of the Spanish Flu epidemic in 1917-18, whenever. It hit the young and the healthy harder which is counter-intuitive. The possible explanations I have read center around the exposure to previous viruses. That is to say, the possibility that the older folks have have been exposed to previous viruses that were sufficiently similar to the spanish flu virus to offer full or partial immunity - but the young people were not. Even in the old days, people knew that having cowpox provided partial immunity to smallpox. I mean, way back, like in the very late 1700's.
The Spanish Flu had a huge variability in mortality over different ethnicities. People of Samoan ancestry had mortality up near 80%. What is fascinating is that the Spanish Flu is thought to have originated in the United States.
Oh, yes of course. The native groups always get hit the hardest. Entire villages of hundreds of people were wiped out in Alaska. But that is/was true of their first expose of measles, chickenpox and all the european white man diseases upon first exposure. The entire native population of north america was reduced by 80% or so with a very short period of time. As an aside trivia, the semi-intact spanish flu virus with its chromosomes was retrieved from a tribal burial ground in western Alaska, where it people had and still are buried below the permafrost. The recovered virus was deactivated but they were still able to piece it together enough to do gene sequencing. Lots of stuff preverved in the permafrost. Hope the thawing does not unleash anything that is unwelcome. Could happen.
When you do... rotate that money into a well picked China pure-play or a China ETF. Let these rumors keep flying and let their markets keep dropping... its setting up to be a generational buying opportunity.