A United States magistrate ruled last week that a class-action lawsuit filed against the Nation's top pharmaceutical companies should be tried in state rather than federal court. The decision was a major victory for plaintiff attorneys. The lawsuit involves a 3-year-old Portland, Oregon boy who was diagnosed with autism after receiving a series of vaccines containing the preservative thimerosal, a form of mercury.

William Mead's parents allege vaccines that contain thimerosal cause autism. In 1999 both the American Academy of Pediatrics and the U.S. Public Health Service recommended discontinuing the use of vaccines made with thimerosal. Nevertheless, doctors remain uncertain of the relationship between the preservative and autism.

Defendants named in the lawsuit include Pfizer Inc., Baxter International Inc., Merck & Co., Sigma Chemical Co., Aventis Pasteur Inc., GlaxoSmithKline, Abbott Laboratories, Eli Lilly & Co., Aldrich Chemical Co., and American Home Products.