Kennedy's efforts to reshape vaccine policies have been well chronicled, but ProPublica wanted to take a broader look at how the changes might affect Americans' health in the years to come. We found that long-forgotten plagues have roared back, killing and maiming children in parts of the world where access to vaccines or trust in them faltered. What seemed like subtle changes to a country's vaccine policies had disastrous consequences years later. Even in places that offer highly advanced health care, doctors have felt impotent trying to undo the damage when these horrors return. Modern medicine can't reverse paralysis from polio. Surgeons can intervene when a baby is born blind, deaf and with heart defects after being exposed to rubella in the womb, but the child is still likely to face a life shaped by disability.