I have never had the flu either and I am in my mid-50s. I have always wondered if it had anything to do with my great-grandmother who got the flu while breastfeeding my grandfather. She died shortly afterwards but of pneumonia, not the flu. I can’t recall my mother having the flu, and I don’t know if my grandfather ever had it. Perhaps some of the survivors descendants also carry some immunity?
I have always wondered: If anti-bodies from a parent can be acquired by a breast-feeding child, and if the anti-bodies are acquired through the feeding, how do the anti-bodies survive the digestive process to be absorbed by the body intact?
It works that way with parvo. If a mother dog has lived through the virus, her pups are immune as far as I know.
The continuing immunity to the flu probably is a proxy for a whole bunch of other immune system characteristics that contributed greatly to the fact that these individuals lived into their 90’s and 100’s.
Since, I’ve read, about up to 75% of people in their late 70’s have some type of cancer (whether or not it becomes a manifest disease process for them), folks that live into their 90’s and 100’s also apparently have “immunity” to cancer, heart disease and stroke as well.
You used to hear the description, “Grandma has a strong constitution.” That is likely a statement of biological as well as genetic fact.
But still producing antibodies 90 years later-—WOW!