The AIDS Titanic

Jay and Nancy Mone jaymone at PAONLINE.COM
Fri Jan 29 20:49:25 EST 1999

The example of SIV changing it's route of transmission is wrong.  As far 
as we know, SIV has always been transmitted naturally by sex.  For HIV 
the same holds true.  Nothing about the basic biology has changed.  The 
addition of needles is not natural, so can't be used as an example either.
Many factors are involved in determining whether a virus can replicate in 
a given type of cell.  Since mosquito cells don't express the receptors 
required for HIV entry, the virus would need not merely a variation in 
it's spike proteins, but a completely different spike.  I guess such a 
thing is possible, and maybe I'll run a sub-4 minute mile before I'm 50, 
but I doubt it.
When SIV jumped ship from monkeys to humans (if indeed you believe that 
SIV is the ancestor of HIV), it didn't really need to change too much.  
The cells of both species are similar in many respects, including 
receptors, and the virus probably needed relatively few changes to 
initially establish infection in humans.
Think about it...no retroviruses that we know of are transmitted by 
arthropod vectors.  Neither are influenza, herpes, or hepatitis.  Why not?

Jay Mone' 

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