WASHINGTON — The Supreme Court on Tuesday shielded the nation's vaccine makers from being sued by parents who say their children suffered severe side effects from the drugs.

By a 6-2 vote, the court upheld a federal law that offers compensation to these victims but closes the courthouse door to lawsuits.

Justice Antonin Scalia said the high court majority agreed with Congress that these side effects were "unavoidable" when a vaccine is given to millions of children. If the drug makers could be sued and forced to pay huge claims for devastating injuries, the vaccine industry could be wiped out, he said.

The American Academy of Pediatrics applauded the decision. "Childhood vaccines are among the greatest medical breakthroughs of the last century," said Dr. O. Marion Burton, the group's president. "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."