[exDemMom]

People of European descent, whose ancestors survived the black death, commonly have a particular immune system variation that is only found rarely in other races. It is thought that this particular variation helped those ancestors survive. That variation could be the basis of the hardiness that Dr. DeWitte has observed.

[djf]

You are speaking about the Delta-32 mutation, which affects (now) about ten percent of the population.

It yields white blood cells that have a variation of the membrane that make it impossible for yersina (or hiv) to infect them.

No doubt it was increased by the plague, but I doubt that was the only factor.

[5th MEB]

So far I have survived every thing the world has thrown at me for my sins. Valley Fever in 64, almost burned to death as a USFS firefighter in 67, Tet offensive in 68, Malaria in 70, brain tumor in 82(they cut it out of my head and installed a 3”x4” plate), some strange virus in 90 (crippled me up for about 4 weeks and quarantine) that they never identified, Lyme disease in 2001, rabies in 2012( got the shots and didn't chew up the furniture) and pneumonia 5 times so far in my life, smoker since I was 11 years old and still ain't dead.
Guess God has a plan for me, just haven't figured it out yet.Either that or I am just one of those old evil white guys of Norther European ancestry that will just keep on keep'in on.