WASHINGTON — The United States Court of Federal Claims began another hearing on Monday to decide whether a vaccine additive led thousands of children to become autistic.
The hearing is the second in a series of three in which the court is considering whether the government should pay millions of dollars to the parents of some 4,800 autistic children. In this hearing, parents are claiming that thimerosal, a preservative that contains mercury, damaged their children’s brains. Thimerosal was removed from all routinely administered childhood vaccines by 2001.
Every major study and scientific organization to examine the issue has found no link between vaccination and autism, but the parents and their advocates have persisted.
The claims are being heard in a special court set up by Congress 20 years ago when a series of scares nearly crippled the vaccine industry. The hearing is expected to last two to three weeks, and a decision is not expected until next year.
Almost absent from this hearing and the others in the series is any discussion of the case of Hannah Poling, an autistic 9-year-old from Athens, Ga., who the government conceded last year might have been injured by vaccines. Vaccine critics say the concession gives strong evidence that vaccines cause autism, but government officials say the case proves nothing regarding the safety of vaccines.
The experiences of two 10-year-old boys from Portland, Ore., are at the center of the latest hearing. The boys, William Mead and Jordan King, were developing normally until they were vaccinated, said Thomas Powers, a lawyer representing them.
But a buildup of mercury in their brains from vaccines containing thimerosal led the boys to regress, Mr. Powers contended.
The claims for the two boys are test cases being heard to determine whether parents in thousands of similar cases should receive compensation. Last summer, Mr. Powers presented before the special court the test case of Michelle Cedillo, who Mr. Powers claimed was injured by both vaccines containing thimerosal and the vaccine for measles, mumps and rubella, which did not contain thimerosal.
Next summer, the court will hear a test case in which lawyers will argue that the measles, mumps and rubella vaccine was the sole cause of autism.
Plaintiffs and their lawyers have sought for years to delay hearings on their vaccine claims, hoping new research or government data would bolster their arguments. But with each passing year, the claim that thimerosal had an important effect on children has become harder to sustain. Its removal has appeared to have no effect on autism rates.