Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!orion.oac.uci.edu!ucivax!ucla-cs!DGREEN@IBM.COM
From: DGREEN@IBM.COM (Dan R. Greening)
Newsgroups: sci.med.aids
Subject: Re: Question about GP160 vaccine trial
Message-ID: <40273@shemp.CS.UCLA.EDU>
Date: 17 Oct 90 20:59:31 GMT
Sender: news@CS.UCLA.EDU
Reply-To: dgreen@cs.ucla.edu
Lines: 49
Approved: phil@wubios.wustl.edu
Note:	Copyright 1990 by Daniel R. Greening.  Permission granted for
Note:	non-commercial reproduction.
Archive-number: 2655

Steve Hanks wrote:

| I've just begun the process of volunteering for a
| GP160 vaccine trial.  Before I went for my first
| visit I spoke to a friend who's part of the NIH
| trials using the same vaccine;  he mentioned that one
| drawback associated with receiving the vaccine was that
| there was the possibility that you might not be able
| to be vaccinated at some point in the future, if, for
| example, a different effective vaccine were found.

Hi Steve!  (Please say "hi" to your friend for me.)

People at NIH are not particularly sure about the effects of the vaccine.
Hence, it is in a Phase 1 or 2 trial.  I raised some of the same questions
you did, and the answer didn't seem very clear.  The bottom line is that
nobody knows.

The only plausible scenario I could construct for inhibiting a future
vaccine is this:

  You get immunized to gp160 protein.  Later, someone develops a
  live-virus type vaccine:  an engineered vaccine which incorporates
  gp160 plus some other HIV proteins (p24, p41, etc.) into an otherwise
  innocuous foreign invader (like vaccinia virus, for example).

  OK, now someone gives you the engineered live-virus.  Perhaps you have
  developed sufficiently high antibody levels to gp160 that you immediately
  kill the innocuous invader.  So... you don't develop high antibodies to
  the other proteins.

  Make sense?

A similar scenario actually happened, I believe, with the vaccinia HIV
vaccine:  The engineered vaccinia included some protein from HIV (gp120?
I forget what.)  They innoculated several people with it.  However, those
who had received vaccinia-polio vaccine FAILED to produce high antibodies
to HIV proteins.  Why?  Because they had ready-antibodies to other proteins
in the vaccinia virus, and it was immediately killed--before raising the
antibody levels of the HIV proteins.

If I have made mistakes in this analysis, I welcome corrections.

This didn't stop me from being involved in the study, though.

--
____
\  / Dan Greening	12 Foster Court			NY (914) 784-7861
 \/  dgreen@cs.ucla.edu	Croton-on-Hudson, NY 10520	CA (213) 825-2266