The majority said that Congress found such a system necessary to ensure that vaccines remain readily available, and that federal regulators are in the best position to decide whether vaccines are safe and properly designed.
The National Childhood Vaccine Injury Act of 1986 "reflects a sensible choice to leave complex epidemiological judgments about vaccine design to the FDA and the National Vaccine Program rather than juries," Justice Antonin Scalia wrote, referring to the Food and Drug Administration.
Justices Sonia Sotomayor and Ruth Bader Ginsburg dissented, saying the threat of lawsuits provides an incentive for vaccine manufacturers to constantly monitor and improve their products.
The decision "leaves a regulatory vacuum in which no one - neither the FDA nor any other federal agency, nor state and federal juries - ensures that vaccine manufacturers adequately take account of scientific and technological advancements," Sotomayor wrote.
The decision is a victory for vaccine-makers such as Wyeth and GlaxoSmithKline. Kathleen Sullivan, who represented Wyeth in the case before the court, told justices that ruling against the company could lead to thousands of lawsuits in which parents claim, for instance, that the mumps, measles and rubella vaccine played a role in their children's autism.
It also marks another chapter in the court's evolving jurisprudence on "preemption," the question of when federal laws and regulations displace state actions or lawsuits. Those questions often divide the court on ideological grounds, but in this case, liberal Justice Stephen G. Breyer joined the court's consistent conservatives.
The Obama administration also backed the vaccine makers, and Justice Elena Kagan was recused because of her work on the case as Obama's solicitor general.
The case was brought by Russell and Robalee Bruesewitz on behalf of their daughter Hannah, 18. Hannah began to have seizures as an infant after receiving the third of five scheduled doses of Wyeth's Tri-Immunol diphtheria-pertussis-tetanus vaccine. The company, now owned by Pfizer, has taken the drug off the market.
The 1986 federal law said that all such claims must first go to a special tribunal commonly called the "Vaccine Court." The program has awarded nearly $2 billion for vaccine-injury claims in nearly 2,500 cases since 1989. It is funded by a tax on immunizations. But the tribunal ruled against the Bruesewitzes, saying they had not proved that the vaccine harmed Hannah, who will need life-long care.
The couple then sued under Pennsylvania tort law. The company had the case moved to federal court, and judges have consistently ruled that the suit cannot proceed, because federal law prohibits claims against "design defects" in vaccines.
The justices at oral argument debated ambiguous wording in the federal law. It says that no vaccine maker can be held liable for death or injuries arising from "side effects that were unavoidable even though the vaccine was properly prepared and was accompanied by proper directions and warnings."
Scalia said the word "unavoidable" would be meaningless "if a manufacturer could be held liable for failure to use a different design."
Sotomayor read the language to mean the opposite, and said "text, structure and legislative history compel the conclusion that Congress intended to leave the courthouse doors open for children who have suffered severe injuries from defectively designed vaccines."
Consumer groups and others had supported the Bruesewitzes, but the American Academy of Pediatrics applauded the decision.
"Today's Supreme Court decision protects children by strengthening our national immunization system and ensuring that vaccines will continue to prevent the spread of infectious diseases in this country," AAP President O. Marion Burton said in a statement.