How come some people are immune to even horrific diseases?

[raccoon]

remember in THE STAND a small percentage of people didn't get the flu? Yes, I know
it's fiction.

In RL, on some news show they mentioned a prostitute in Africa who's been exposed to
AIDS but never contracted it.

[surrealAmerican]

1. Sometimes, it's prior exposure to a similar virus ...

... sometimes, it's a random mutation.

[NoOneMan]

2. We don't age either, she wasn't actually a prostitute and some cows do in fact have brown milk

The secrets of the universe are not for sale

[a la izquierda]

3. There have been genetic studies into this...

looking at how people survived the plague. The CCR5 gene is thought to make people immune.
http://en.wikipedia.org/wiki/CCR5

[indepat]

6. The luck of the draw. My father started using tobacco at the age of six and continued

until the end at 96. Who knows if the tobacco contributed to the heart attacks (2) that eventually felled him. For more than 50 years, he had been burying contemporaries who died from smoking-related diseases. So, it's likely mostly in the genes.

[virgogal]

10. Wow! Your father probably saw friends buried before him that

never even smoked at all.

Great genes--lucky you.

[TexasBushwhacker]

4. And they should be studying her blood and immune system like crazy

No disease is 100% contagious or 100% lethal. There will always be people that have natural immunity for whatever reason. I know that many people will disagree with me, but I think that when they find people who are at high risk for a disease like HIV, HPV or Hep C, and they DON'T have it, they should be studying those people and I think the more people that get tested the more of these super-immune folks we could find. It seems like the normal MO for studying a disease is to study the sick people. Maybe we need to be studying the well people.

Another example is the mutations in BRCA1 and BRCA2 genes for breast cancer. The way it is now, if a woman finds out she has one of these genes she can worry that she'll get breast or ovarian cancer or she can get a prophylactic mastectomy and or oopherectomy (removal of the ovaries). But what about the ones who DON'T get breast or ovarian cancer. Are they studying them at all?

[Sekhmets Daughter]

5. I don't get the flu...

I'm almost 65, I've never had it and neither have my children.

There are people immune to plague as well. That's genetic.

[a la izquierda]

7. I've never had the flu in my life...

and last week I was in a house with two people who had it. I got a flu shot...but so did they. I very rarely get sick and when I do, it blows through in less than 24 hours.

[Sekhmets Daughter]

14. I've never had a flu shot either.

I've been vaccinated for smallpox 4 times, no scarring...because of natural immunities which prevent the injection site from festering. When I was in college my entire dorm floor was sick with the flu, except me. I nursed 20 girls...yuck.

[Blue_In_AK]

8. The last time I had the flu was 1968,

and I don't get vaccinated. I hardly ever even get a cold. I thought maybe it was because I'm not around kids that much, but in November I spent two weeks with my little grandchildren who both had snotty noses and coughs, and I didn't even get a sniffle. Lucky, I guess.

[Quantess]

9. Yes, I'm sure you'll get a scientific answer when you throw a general question out to the DU...

Just wait, the scientists will be pounding the door any second now, fighting amongst each other to provide the most scientific answer...

/sarcasm

[Science Geek]

11. Bubonic Plague exposure in Europe....

....is thought to provide, for some population of European ancestry, immunity to HIV by causing slight genetic changes perhaps over generations. They may still contract the virus, but it does not seem to multiply out of control, or cause illness, in those individuals.

[cthulu2016]

12. Probably a normal range of genetic variation in immune systems

Things that infect us are very narrowly tailored to the host. I would think that germs evolve to infect enough people to keep going, but there is not enough evolutionary pressure to need to crack the ocassional tough nut.

[Science Geek]

13. Punctuated equilibria...

A lot of discussion in biology circles theorizing that in addition to periods of high gamma-ray influx from space, that other factors, especially multi-generational viral exposures may cause genetic mutations, and that especially large viral outbreaks may cause the SAME genetic mutations in relatively large groups of animals within the same species and then these are reproduced in their offspring.

Hard to prove anything that takes several generations to occur.