Updated

Drug manufacturers are a step closer toward winning the liability protections they say they need before investing in medicines to combat a bird flu pandemic.

Opponents described the protections, approved early Monday by the House, as a "massive Christmas bonus to the drug companies."

Consumers seeking damages on claims they were harmed by a vaccine would have to prove willful misconduct on the part of the drug manufacturers. That is a higher standard than negligence, used in many product liability cases.

"Negligence is much easier to prove; it's the failure to exercise reasonable care," said Carl Tobias, a professor at the University of Richmond School of Law. "Willful misconduct is a much higher standard. You must intentionally misbehave. ... The high standard would clearly discourage many suits."

Senate Majority Leader Bill Frist, R-Tenn., led the fight for the additional protections. Amy Call, a Frist spokeswoman, said drug companies don't view flu vaccine as profitable and won't get in the business if the potential liabilities outweigh the potential benefits.

"When you're asking a company to come in and develop something new that they won't make money off, ... there's no reason for them to get into the market," Call said.

Frist attached the legislation to the Defense Appropriations Bill, a bill viewed by lawmakers as must-pass because it will fund military operations in Afghanistan and Iraq. The Senate will take up the bill Wednesday or Thursday.

Democrats opposed attaching the liability protections to the defense bill, as well as the substance of the legislation.

"This liability shield can be granted to any product used to prevent or treat an epidemic or a pandemic, and the secretary gets to decide what that means. No court can review that decision," said Rep. Henry Waxman, R-Calif. "But for those who may be injured, Washington Republicans had only a lump of coal: a compensation program without a single penny of funding. "

Trial lawyers also attacked the legislation.

"In the dead of night when no one was watching, U.S. Senator Bill Frist provided his corporate friends in the drug industry with an unprecedented giveaway that puts the health and safety of Americans at risk," said Ken Suggs, President of the Association of Trial Lawyers of America.

"The trial lawyers apparently would prefer to keep filing frivolous lawsuits and collecting excessive attorney fees rather than making sure public health is protected and injured parties are compensated," Call replied.

Call said the legislation puts in place a compensation system modeled after what Congress approved for those who experience harmful side effects from the smallpox vaccine. Under the program, pandemic flu vaccine recipients or their families could apply for lost income, medical expenses and death benefits.

But Democrats said the legislation appropriates no money for the compensation fund, and they question whether Republicans ever will fund it.

The defense bill also sets aside $3.8 billion for improved pandemic preparedness — but that's just slightly more than half of what the president requested a few weeks ago.

Fears of a pandemic have increased in recent months as a virus infecting millions of birds has spread throughout Asia and parts of Europe. While the virus has not yet appeared in the United States, or spread from person to person, officials worry the bird flu could eventually mutate and create a global health crisis because people have no immunity to the virus.

Most of the funding, about $3.3 billion, would go to the Department of Health and Human Services, mostly for the purchase of vaccines and antivirals, for state and local planning, and for improved surveillance.

A spokesman for the department said the appropriation was in line with what the administration had planned on spending this year — even though it's much less than what the president requested.

"It's a good start and we'll be back next year to continue the work," said HHS spokeswoman Christina Pearson.