Here are some quotes from a N.Y. Times article. The case turned on the proper interpretation of a provision of the law that bars ordinary lawsuits “if the injury or death resulted from side effects that were unavoidable even though the vaccine was properly prepared and was accompanied by proper directions and warnings.”
Justice Scalia acknowledged that “Congress could have more tersely and more clearly pre-empted design-defect claims.” But he said the meaning of the passage was not in doubt. “If a manufacturer could be held liable for failure to use a different design,” Justice Scalia wrote, “the word ‘unavoidable’ would do no work.”……
Justice Sotomayor, joined by Justice Ruth Bader Ginsburg, said the majority opinion “disturbs the careful balance Congress struck between compensating vaccine-injured children and stabilizing the childhood vaccine market.”
Justice Sotomayor said she understood the word “unavoidable” differently in the context of the law than Justice Scalia did. She said it indicated that Congress must “have intended a vaccine manufacturer to demonstrate in each civil action that the particular side effects of a vaccine’s design were ‘unavoidable.’ ”….
The effect of Tuesday’s decision, Justice Sotomayor continued, was to leave “a regulatory vacuum in which no one ensures that vaccine manufacturers adequately take account of scientific and technological advancements when designing or distributing their products.”
In a final footnote, Justice Sotomayor wrote that a concern about an asserted link “between certain vaccines and autism spectrum disorders” appeared to “underlie the majority and concurring opinions in this case.”
Apparently even Supreme Court justices argue over the definition