If you were born in the 50s and lived for over 60 years, you have SOME immunity to most variants of the flu.
But if a new one comes along, you could be in trouble.
Vaccine? Rarely hits the variant.
And we learned very early that vasccinations were the only way to protect a populace, so we developed extreme and strict vaccination rules and laws and we pretty much did away with smallpox, diptheria, polio etc., etc.
Until around 30 years ago when we were being invaded with unprotected people from God awful places that didn't know you use paper, not your left hand.
THAT is where it all started.
I'm a boomer with the moon crater booster mark on my shoulder to prove it, and I have never had the flu shot, but at almost 72, I'm just now sort'a gettin' over a flu two weeks running.
I've never really been sick in my adult life (until now) and when I was, my wife would baby and nurse me back to health and off I'd go to work again.
Shut down the borders and give our medicos a break and a chance to catch up.
So, from what’ you’re saying: us folks who’ve been around the block a few times have built up resistance to flus we’ve encountered. And if it’s a new variation, the vaccine probably won’t do any good.
Part of the immunity of elderly to flu viruses could also be due to the fact that we grew up in the 1940-50’s. We were allowed to play outside in the dirt, run behind the trucks fogging our neighborhood with DDT, going barefoot without shirts and only cut-off old jeans. Lots of bleeding from minor scrapes and cuts. Lots of Vitamin D from Sunshine! We had measles, mumps and others that helped to build our immunity to many things
Then along came the “helicopter” and “soccer” moms who wont
even let their kids walk a few blocks or a mile to school.