Wearing noise-canceling headphones, Michelle, of Yuma, Arizona, was brought into the courtroom in a wheelchair at the start of the proceedings before the U.S. Court of Federal Claims. She stayed only a short time.
Her parents, Theresa and Michael Cedillo, allege that a preservative called thimerosal that had been used in vaccines weakened their daughter's immune system and prevented her body from clearing the measles virus after she was immunized for the disease at age 15 months.
Today, Michelle suffers from a long list of health problems, including severe autism, inflammatory bowel disease, glaucoma and epilepsy.
The 12-year-old girl’s parents demand payment under the National Vaccine Injury Compensation Program, a no-fault system that has a $US2.5 billion ($A2.9 billion) fund built up from a tax on vaccines of 75 cents a dose.
The battle royal is a test case having wide ramifications.
Since 1999, more than 4,800 families have filed claims with the government alleging their children developed autism as a result of routine vaccinations containing thimerosal.
The court is being asked to decide whether there is a link between autism and childhood vaccines. If it finds one exists, the families could be eligible for compensation under the Vaccine Injury Compensation Fund, a program established by Congress to ensure an adequate supply of vaccines by safeguarding manufacturers from lawsuits. Under the program, people injured by vaccines receive compensation through a special trust fund.