Could there be a cure for type 1 diabetes? It looks like we're headed in that direction. A "reverse vaccine" that targets the cells that attack insulin producers seems to have passed its first test in humans. In type 1 diabetes, the immune system typically attacks insulin-producing cells for reasons scientists still don't quite understand. So what makes the vaccine a reversal? Unlike normal vaccines, which train the immune system to destroy a certain kind of cell, this treatment instead suppresses immune cells to keep them from doing the same thing. Experts say the therapy needs to undergo much more testing before it's put on the market. But it's an exciting step.