Finnish HIV Vaccine Testing To Begin 72
First time accepted submitter ultranova writes with news of a new phase in trials for an HIV vaccine. From the article: "Some 1,000 patients throughout France and Switzerland will take part on the trials, with the first phase involving hundreds of HIV sufferers. Participant numbers will increase as the program progresses. ... According to Reijonen, the GTU technology developed by FIT Biotech is also suitable for use as a preventive HIV vaccine, however, he says that such a drug is still ten years away.The central idea behind HIV vaccine development is the use of genetic immunization. Genes are introduced into the body in order to generate a controlled immune response against HIV. Gene Transport Unit (or GTU) technology refers to FIT Biotech’s patented method by which genes can be safely introduced into the body."
Prophylactic vs. Therapeutic Vaccines (Score:5, Interesting)
The issue here is the distinction between Prophylactic Vaccines and Therapeutic Vaccines .
The OP's confusion is understandable, as the vast majority of vaccines in clinical use are purely Prophylactic in nature, functioning solely as preventatives; these have little or no utility when administered after infection has taken place. Such vaccines are typically heavily dependent on Humoral Immunity [wikipedia.org], which may take several weeks time to reach maximum effectiveness, and maybe an additional dose or two.
This delay means the vaccine is of little use in acute infectious diseases (which run their course in a relatively short length of time). In chronic diseases, the infectious agent may be around longer, but usually by that time the immune system is already generating an appropriate response to the naturally occurring disease agent -- in other words, the advantage of the vaccine was purely in helping the immune system get there "first-est with the most-est", and you've already lost that advantage in waiting.
The number of Therapeutic Vaccines is relatively small, but a good example of one such entity is the Rabies Vaccine (which is both a Prophylactic and Therapeutic Vaccine) -- which manages to work post-exposure in part due to the time lag before the virus succeeds in penetrating the central nervous system. The case for most HIV therapeutic vaccine candidates I've seen, is in the argument that an HIV infection mis-directs the immune system that can be corrected; most such candidates attempt to enhance the Cell-Mediated [wikipedia.org] Immune response, which appears to be particularly vital to the anti-HIV immune response. However, several such agents have been tried in the past, and all have failed in testing.