you can't inherit immunity. There has been some thought that anybody that was exposed in 1918 would probably still have at least some immunity but nobody really knows for sure.

If that strain or one equal to it was released now it wouldn't have anywhere near the impact it did in 1918 because a vaccine against it could be raised relatively quickly. In addition treatments post infection have improved enough that even with an unchecked pandemic it wouldn't be quite as catastrophic.

Research on monkeys finds resurrected 1918 flu killed by turning the body against itself
Updated 1/17/2007 1:14 PM ET

WASHINGTON — Monkeys infected with a resurrected virus that was responsible for history's deadliest epidemic have given scientists a better idea of how the 1918 Spanish flu attacked so quickly and relentlessly: by turning victims' bodies against them.

The research, which found that an over-stimulated immune system killed even as it tried to fight the flu, helps explain why many of the 50 million people who died in the epidemic were healthy young adults. Conventional flu usually claims mostly the very young and very old.

This new look at an old killer gives doctors ideas on how to fight the current bird flu if it develops the ability to spreads from human-to-human, as many scientists fear it will. The 1918 virus, which was reconstructed with reverse genetics, exists today only in two labs where scientists are studying it.

<snip>

The virus was reconstructed from tissues of victims from 1918. Besides the Public Health Agency of Canada's lab in Winnipeg, it exists only at the Centers for Disease Control in Atlanta.

more...

http://usatoday30.usatoday.com/tech/science/discoveries/flu-research.htm

immune system. But specific immunity to that virus or any other cannot be passed on to offspring.

And yes, I have postgraduate education in immunology and virology so I know a little bit about the subject, FYI.

I saw a show about it on one of the education channels about 2 years ago.

better immunity to organisms that share a certain characteristic.

In molecular biology class we read a paper that suggested that some people, mostly of European descent, whose ancestors were also immune to Plague, are immune to HIV.
I remember reading that some people may be immune to the virus that causes mono. I remembered it because it would explain why my father did not get it from my mother when she had it. My sister and I never got it despite having multiple boyfriends who got it while we were dating.

catching and surviving a disease. It's natural immunity. There's a difference.

You are, of course, correct in that the OP is wrong to suggest and inherited immunity. An acquired immunity (immune response to the pathogen) is not then written into the genes to be passed along to the next generation.

Practical evolved immunity is, however. The generation born to people who had been alive in 1918 was more resistant to the Spanish flue because 50 million people who were highly susceptible had been removed from the gene pool.

Had another wave of the 1918 flu swept the world in 1940 it would have further "distilled" the typical human immune system, vis-a-vis the 1918 flu.

But since it did not, there was nor selection pressure on that generation. And with the selection pressure removed, the second generation would b, statistically, less naturally resistant.

So though acquired immunity is not inherited, people today are, statistically, probably more susceptible on average than people in 1950 were. And probably still a tiny bit less susceptible than people in 1916.

There are some people who are immune from the Black Plague which, unlike Bubonic Plague, is caused by a virus. However, what they have inherited is a mutation of a specific gene. It's more complex but that's all I remember from the show I watched.

Here's the thing I have always wondered about. Both of my parents had received multiple Small Pox vaccination, my mother because she was an immigrant and my father because he served in WW II. When I was a child you had to have a small pox vaccination to enter elementary school. I was vaccinated twice and neither did the normal festering that leads to scarring. My brothers were the same. When I went to college I needed another vaccination and the same thing...no festering, no scarring and again the doctor determined I was already immune...which surprised him as he had expected I would have outgrown the childhood immunity by then. A third attempt several years later had the same results.

Furthermore, I have never had any type of flu and I've been exposed many times. I never get flu shots. I think there is more that doctors don't know than stuff they do when it comes to infectious diseases.

During the Spanish Flu epidemic she picked up prescriptions and delivered medicines for a pharmacist, riding her bicycle. All his regular delivery people were sick.

I wish I had her immune system. I've been knocked down hard by the flu a few times.

She was about 5 months pregnant and already had four kids, my dad was the oldest at 5 1/2ish , on down to about 10 months. They lived in Billiings, Montana and my dad said she got sick and was dead in 3 days.