hanks@cs.washington.edu (Steve Hanks) (10/17/90)
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. Today was my first visit, and I asked the doctor about this. He said that while it was likely that I would be excluded from subsequent *clinical trials* for vaccines, he knew of no medical reason why I wouldn't be able to be vaccinated in the future. The study's consent form, on the other hand, contains the following sentence: Receiving this test vaccine might impair your ability to receive other potential AIDS vaccines which may be available now or in the future. which seems to indicate a probelm more than just being unable to enroll in subsequent trials. The doctor continued to maintain that it was just a question of enrolling in trials, but I checked with my friend afterwards, and he was quite sure that there was actually some possible medical complication (though he wasn't sure what). I was wondering if anybody had information on this question. Thanks much, Steve hanks@cs.washington.edu
DGREEN@IBM.COM (Dan R. Greening) (10/18/90)
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