With her crimson curls and angelic face, little Hannah Poling, a 9-year-old girl with autism, hardly looks like a pioneer. But the Georgia native is the first to receive a mea culpa of sorts from federal health officials, who acknowledged that routinely recommended vaccines she received as a toddler might have contributed to her autism. Poling's case is unique in that she received five injections in one day in order to catch up after falling behind the recommended vaccination schedule. More important, she also has a rare mitochondrial condition that disrupts normal cellular function; this, experts believe, was worsened by the immunizations, causing brain changes. It's one more data point in the continuing war over whether childhood immunizations are linked to autism; scientific studies to date and the Centers for Disease Control and Prevention find no consistent cause-and-effect relationship.