While some viruses attack the lungs, and others the blood, HIV attacks the only system that could put up a fight: the immune system itself. The immune system mounts some defense, but after HIV launches its surprise attack, the body simply can't produce enough killer T blood cells to take out the virus.
Now, thanks to researchers at UCLA, it's payback time for the blood cells. A team of scientists have plucked T-cells out of someone infected with HIV, and used them as a template for creating an army of HIV-fighting immune cells out of stem cells. Essentially a genetic vaccine, this technique could be used to copy T-cells designed to fight any virus, opening up the possibility of universal vaccination via stem cell implantation.