From: weemba@sagi.wistar.upenn.edu (Matthew P Wiener)
Newsgroups: alt.folklore.urban,soc.culture.african.american,sci.skeptic
Subject: Re: AIDS and the CIA (was Question)
Date: 15 Nov 92 20:16:35 GMT
Reply-To: weemba@sagi.wistar.upenn.edu (Matthew P Wiener)
Followup-To: sci.skeptic
Organization: The Wistar Institute of Anatomy and Biology
In-reply-to: SCW112@psuvm.psu.edu

In article <92318.150807SCW112@psuvm.psu.edu>, SCW112@psuvm writes:
>Well, what HIV does is it has the ability to insert a copy of it's
>genetic material into the host's DNA. Most viruses just infect a cell
>and force it to create a whole lot of copies of itself (killing the
>cell in the process).  That's why HIV remains dormant -- It's sitting
>inside your DNA until something (some environmental factor) turns it
>on and you get AIDS.

This is unknown.  As a retrovirus, HIV forms DNA instructions for itself
in host cells, and they join in with the rest of the chromosomes.  The
cell at some point uses the viral DNA as if it were its own, repeatedly.
It will do this without any special environmental factor.  Retroviral
infection is, in fact, a common technique in the recombinant DNA world.

This, in itself, is no reason why the immune system cannot get at it.
Foreign bits inside a cell end up having molecular parts show up on
the surface of infected cells.  The right killer T-cell finds these
and destroys the cell.  The process is much slower with a retrovirus
than a normal virus, but otherwise the same.

>As to the reason why we don't have an HIV vaccine, it's easy to make
>a vaccine.  All a vaccine is is like a part of a virus that provokes
>the immune system to create antibodies against that virus. We could
>make an AIDS vaccine right now, I'm sure.

No, we can't.  A vaccine has to induce the correct immune response.
We do have trial AIDS vaccines though.

>					   Thing is, because you're
>using the virus, there's a chance you might get the disease (a real
>small one, but a chance). What experimental human subject is gonna
>take that chance?

Many have taken the chance, so that's not the issue.

>		   Plus, a vaccine immunizes a person because that guy
>will have the antibodies to fight off the virus when he gets exposed
>to it.

That is correct.

>       Thing is, our HIV antibodies aren't real good at fighting off
>HIV. So even if we had them, it wouldn't much matter.

It is unknown why our body's response to HIV is a failure.  This unknown
is a major stumbling block in theorizing, let alone designing, an AIDS
vaccine.  The models that make the most sense to me say HIV uses judo.
The immune system is thrown against the virus, and it misses, badly.
If so, tinkering with this will not be easy.

>So making a vaccine against AIDS is difficult because you want to use
>a part of the virus that will provoke an immune response but not give
>you AIDS.

That is only part of the problem, although a minor one according to
most researchers.  The other difficulty is HIV's high mutation rate.
It's hard to hit a moving target.

>	   The fact that HIV is a retrovirus really has nothing to do
>with it.

That is correct, although it being a retrovirus makes the situation more
difficult.
-- 
-Matthew P Wiener (weemba@sagi.wistar.upenn.edu)
Newsgroups: alt.folklore.urban