cryptochrome's Journal: Vaccine Blues

Up until recently, the only method for dealing with viral illness (aside from just weathering it) has been vaccination. And essentially, a vaccine is just a sort of advance warning to the body's immune system to let it know what to be ready for in the future. Within your immune system is the potential to identify and filter out trillions of different antigens (foreign substances and proteins), given enough time to identify and bring them to readiness. Even without a vaccine most viral illnesses go away on their own as our immune systems catch on the normal way. We have vaccines and/or successful vaccine-development programs for just about every major viral infection known to man - except HIV. After over twenty years of vaccine research, not one has proven itself even partially effective.

Presumably the main obstacle is HIV's pronounced tendency to mutate into new, unrecognized forms. Furthermore, only a handful of viral proteins are actually exposed where the immune system can detect them and the virus replicates at an extremely high rate, essentially giving us a narrow window on a fast moving target. Perhaps most troublingly HIV attacks the very immune systems necessary to defend against it. The full dynamics of neither HIV's attack nor the immune systems defense is well understood. All we know is that no matter what antigen you try to prepare the immune system with, no matter how much time it has to find the proper antibodies on its own, HIV has proven it can outmaneuver our bodies defenses for years and kill us in the end. An increasingly aired view among researchers is that, for the most part, the human immune system is simply incapable of keeping up with HIV's incredible adaptivity.

Nevertheless, there are at least three somewhat unconventional vaccine approaches that may yet bear fruit.

The first are the DNA vaccines. Rather than using live or killed virus, naked viral DNA is blasted into your cells so that they generate viral proteins and thus stimulate the immune system. While this is a novel system that bypasses many of the difficulties of other vaccination techniques and may thus be widely applicable, there is ample reason to think that it will offer no solution to HIV's ability to adapt. Proponents of this novel technique nevertheless remain cautiously optimistic.

The second is not actually a preventative vaccine at all. It is perhaps better described as a therapeutic vaccination technique, which appears to be capable of reducing viral load to a tenth of its normal levels. Essentially it is a way of helping the immune system do its normal job. Dendritic cells are isolated from the patient, then exposed to killed HIV virions purified from the patients own blood. These cells are now primed to specifically target the HIV virions affecting the patient, and a reinjected, where they mount a massive sustained attack on the virus. The treatment is believed to be effective for about a year, has no side effects apart from swollen lymph nodes, and overall costs less than present drug treatments, which it can be combined with thus enhancing the treatment. But what it definitely is not is preventative.

The third treatment may have actual potential as a preventative vaccine. Again, the biggest problem with HIV is its ability to change - but therefore, if you can find a part of the virus which does not change and target that, it would have no room to maneuver. Researchers in france believe they have discovered just that, and developed a vaccination treatment which appears to work in the lab at the cellular level at least. Furthermore, the vaccine is easy to manufacture and quite cheap. Trouble is, if we could make a vaccine that works then why can't your own body stumble onto that response on it's own? Indeed, in the original paper announcing this research is a table indicating at least some AIDS patients already possess this activity. Nevertheless, it is worth at least trials in vivo.