From Edge:
[KARY MULLIS] We're working on a way to manipulate the existing immune system so it can attack things it's not already immune to. We've been controlling bacteria for years with antibiotics, but the bacteria are catching on. We've never been good at controlling viruses unless we prepare for them well in advance by vaccination, but now we can use the same method for them too, and in both cases the cure is not administered until you are infected, and it works right away. It sounds to good to be true, so did antibiotics—they called them “miracle drugs.” In order to understand what we're doing, I should explain how the immune system works. Most people know you've got this system, but not how it actually functions down on the level of molecules and cells.
It's a collection of lots of different kinds of cells, each with their own purposes. There are about as many as you have in your brain distributed mostly in special areas all over your body. The business end of the system is a set of hungry cells that will destroy and ingest things that are designated by the whole system as being “other.” The rest of the system is charged with preventing them from eating anything else. New cells are always being born. And they are right away tested for their ability to make antibodies that attach themselves onto things that are “other”. Antibodies are molecular markers.
More here.
