Over the years, about $1.5 billion has been paid out in compensation and legal fees for more than 1,800 families, most of which would have had little chance of winning a civil trial, the officials said. They insisted that the vaccine court was less adversarial than civil courts, but said they were obliged to fight claims that weren't based on good science.
This was "never intended to serve as compensation source for ... conditions that are not vaccine-related," said Joyce Somsak, the program's acting director.
But in trying to weed out undeserving claims, critics say, the government has insisted on a level of proof of injury that is almost impossible to meet.
And a Times analysis of claims data shows that the court has become more unyielding over time: Officials are much less likely than in earlier years to concede that a vaccine was responsible for an injury or death. The percentage of people getting awards also has declined.
Even when families do win compensation, officials have sometimes battled them over just a few dollars.
In one case, government representatives argued that $150 a year was too much to spend on wheelchair maintenance. They have haggled over how much to allow for replacement shoes and braces for people with polio. Another time, they recommended rubber sheets for the bed of an incontinent person because they were cheaper, although less comfortable, than disposables costing $135 a year.
"We never anticipated the extent [they] would go to deny these kids compensation," said Barbara Loe Fisher of the National Vaccine Information Center, who lobbied for the bill that created the program.
Viewed another way, by being tightfisted, officials have been good stewards of the vaccine injury trust fund, the self-insurance pool that pays awards to the injured. In fact, the fund -- fed by a surcharge of 75 cents per vaccine dose -- has ballooned to more than $2 billion, while earning about as much in annual interest as it pays in awards.
But the fund was not meant to be a moneymaker. The idea was that it was better to "err on the side of compensating the victim," said Rep. Henry Waxman (D-Los Angeles), sponsor of the legislation.
Roots of the Program
Along with clean water and sanitation, mass immunization ranks among the great milestones in public health. Among its glittering achievements: Measles cases in the U.S. dropped from about half a million in 1960 to 42 last year, according to the Centers for Disease Control and Prevention, or CDC.