21.   They avoid the most devastating diseases of old age until their last few years of life.

22.   Traditional vaccines that harness this mechanism have brought many devastating diseases under control, from polio to smallpox.

23.   Unfortunately, half of that number do not know they have this devastating disease.

24.   A clot-dissolving drug signficantly reduces the damage caused by strokes, providing doctors with the first treatment for this devastating disease, researchers said Friday.