The virus responsible for AIDS was identified in 1983, and since that time scientists have been ...

The big problems with HIV which make the road to a vaccine seem much longer than it should take are in the uniqueness of the virus.

First, we cannot instantly create a vaccine to any virus out there, no matter what type of virus it is. These things take time to make. It was years of research which led to a working vaccine for all the diseases we now vaccinate for, from polio, hepatitis, measles, mumps, smallpox, etc. Even the flu vaccine initially took several years to develop, and we have to take some time to develop new vaccines for new strains, even though we've become old hat at making them.

So, in that regard, it hasn't taken an especially long time. Twenty-five years of research may seem like a lot of time, but when you're confronted with a whole new class of disease, learning as much as we have about it in that length of time-- even as it's racing to evolve so quickly-- shows quite a bit of dedication and accomplishment.

Despite the notable fact that those researching the problem have often been crippled by prejudice and hatred on the part of those doling out the money for research, an amazing amount has actually been done in the last quarter century or so to fight this disease and ultimately defeat it.

As we get the process of creating a vaccine for this particular virus down, it will become easier and quicker for us to manufacture new vaccines to guard against the virus as it evolves into new strains. Subsequent vaccines are always much easier to develop than the first one to combat a disease.

The second problem is that HIV likes to mutate a lot more than other diseases seem to, which would greatly decrease the effectiveness of a traditional vaccine since creating a vaccine that was only effective for one or two strains, without taking the others into account, would only offer partial protection against the possibility of becoming infected, a protection which would become increasingly incomplete as the number of new strains you weren't vaccinated against increased.

You also have to couple that with the fact that HIV doesn't go through the usual routes of transmission. Vaccines work by pre-empting your body's immune response. Instead of waiting for you to fight off an illness so your body's immune system can engineer a pattern on which to build its antigens to destroy the virus, vaccines simply supply it the blueprints so the first time you come into contact with the virus itself, your body already has the ability to produce the specific antigens to destroy it without you getting sick.

That's all well and good, except HIV starts off by specifically infecting and destroying the cells which do that, so even if you supply them with the blueprint, by the time the body knows its under attack, it's too late for it to do anything about it.

So, all that put together means we have to be quite a bit trickier than usual in creating an effective advance defense for the little bugger so we don't have to worry about contracting it... but like I said, it only took us twenty-five years or so to figure it out from the first time HIV appeared, so we've actually done pretty well on that road.