"The government has made absolutely no statement about indicating that vaccines are the cause of autism, as this would be a complete mischaracterization of any of the science that we have at our disposal today," Dr. Julie L. Gerberding, director of the U.S. Centers for Disease Control and Prevention, said in a Thursday news conference. "I think we need to set the record straight on that."

The parents of 9-year-old Hannah Poling said the government agreed to pay for her care after conceding that vaccines she was given as a toddler triggered the encephalitis that led to her eventual diagnosis of autism.

Hannah's mother, Terry Poling, said one theory is that her daughter had an underlying mitochondrial disorder that was aggravated by the vaccinations. She said the other theory is vaccinations caused the disorder, The New York Times reported.

The case was handled under the National Childhood Vaccine Injury Act of 1986, which created a no-fault system for people to file injury claims against the federal government, the newspaper said.