[extropy-chat] Training the immune system

[BillK]

On 5/27/06, J. Andrew Rogers wrote:
>
> On May 27, 2006, at 2:21 PM, BillK wrote:
> > On 5/27/06, Martin Striz wrote:
> >> Indeed.  Jared Diamond, among others, suggests that it was trading
> >> routes and exposure to many pathogens that gave the Europeans an
> >> epidemiological advantage over Native Americans.
> >
> > That's called vaccination nowadays, isn't it?
>
>
> Except that in the case of the Europeans the vaccination is passed
> down genetically, and for diseases for which a proper vaccine may not
> exist even today.  Europeans have a rather dirty genome with a rich
> set of mutations that confer resistance or immunity to a surprisingly
> broad range of pathogens, including many that we would not expect
> Europeans to have been exposed to.  The best known example is
> probably the prevalence of a mutation that confers resistance or
> outright immunity to HIV strains.  On the surface, one would expect
> such mutations to show up in African populations where exposure to
> that family of viruses is historically more common.
>
> While there is much argument over precisely why this is more evident
> in European genomes than others, there is supposedly a fair amount of
> evidence in the genome that suggests pathogen resistance mutations
> were more important to the European genetic stock than others, hence
> it accumulated quite a few more.  Or at least, this is the current
> explanation for why the Europeans seemed to give more disease than
> they got -- they had more built-in resistance to pathogens they had
> not been directly exposed to.  All of which makes great fodder for
> disease research, since these mutations often suggest methods of attack.
>

Sorry, incorrect.  The native Americans were mostly killed by
smallpox. Though chicken pox and measles also killed many due to
malnutrition and poor healthcare.  Up to 80% died, by some estimates.

Europeans had little genetic protection against these diseases, as
shown by the many epidemics in Europe. They did have antibodies
protection, through childhood exposure, cow pox exposure and primitive
vaccination-type treatments as smallpox typically killed around 20-40%
of those infected in Europe.

Edward Jenner developed a smallpox vaccine by using cowpox fluid
(hence the name vaccination, from the Latin vacca, cow); his first
vaccination occurred on May 14, 1796.

I agree that there is evidence for some level of genetic protection
against disease in some populations, but that didn't apply in the case
of killing off the native Americans. Even today, only about 10% of the
European population have the genetic mutation that gives some
resistance to HIV, that you mentioned. This mutation is now being
credited to the smallpox epidemics that mostly killed children in
Europe. The smallpox epidemics that selected for the mutation that
helps to resist smallpox also gives some resistance to HIV.

<http://www.sciencedaily.com/releases/2003/11/031120074728.htm>


BillK