From: Robin Hanson (rhanson@gmu.edu)
Date: Sat Feb 05 2000 - 15:40:26 MST
Robert J. Bradbury wrote:
> It seems pretty clear that HIV-1 and HIV-2 have different evolutionary
> histories. While you may make a case that HIV-1 may have come from
> chimpanzees, it looks like HIV-2 came from Sykes' monkey or Mangabeys.
Point granted.
> > Here are the questions to ask:
> > 1) How much have vaccines contributed to health?
>
> While HIV may be the scourge now, clearly in the '50's Polio was
> something that caused a great deal of harm. A brief glance at
> Fields Virology indicates that in the early '50's, Polio was paralyzing
> 10-30,000 people a year.
The US polio death rate was ~1/500 of the total US death rate when
the vaccine was introduced. Not a negligible factor, but surely much
smaller than many other influences on health. And the other vaccines
had even smaller effects on total mortality.
> > 2) How much have great apes contributed to vaccines, over and above
> > what could have been done with other animals?
>
> Also from Field's Virology it seems that the polio virus does not cause
> pathology in mice, only in monkeys and humans. So it is an open
> question whether you could have used anything but primates to develop
> a polio vaccine. Given the costs involved, I suspect researchers only
> use primates when there are no other good alternatives.
Primates were perhaps needed, but not great apes such as chimps.
> I think you can attribute modern health to three things: (1) sanitation,
> (2) antibiotics, and (3) vaccines. ... A fourth factor is the simple
> understanding of germ theory and communicability and getting medical
> practicioners to follow practices that minimized transmission. But these
> factors combined are what has extended average longevity from
> ~30-40 years to ~75 years.
>
This is completely wrong. I'm lecturing my health economics
class on this topic this last week and this upcoming week, and
have been reading up on it for fun & preparation.
(see Sources for: http://hanson.gmu.edu/EC496S00.html )
Medicine overall seems to have very little effect on health. This is the
usual answer from statistical analyses, and from the few controlled
experiments we have. The mortality rates of most diseases treated by
antibiotics didn't change noticably upon the introduction of that treatment.
I don't think we have controlled experiments regarding sanitation, but the
statistical analyses we do have don't show any effect of sanitation on health.
I'd guess that Medicine of all forms probably contributes less than 1 year
to that 40 year increase in lifespan. Since sanitation also doesn't seem
that important, it is a big puzzle why exactly lifespan has increased so.
It is also a puzzle why the US spends 14% of GDP on medicine.
I have theories I've explored a little, but these are definitely open
questions.
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