Increasing fears of a bird flu pandemic are forcing U.S. officials to face up to problems with the country's troubled flu vaccine industry (search).

President Bush was scheduled to meet Friday with the heads of major vaccine companies "to press ahead to expand our manufacturing capacity for a vaccine to address this risk," White House spokesman Scott McClellan said, speaking of the possibility of a bird flu outbreak (search).

On the agenda for the White House meeting is liability, McClellan said. If healthy people suffer side effects from a vaccine, manufacturers can face huge lawsuits, which is one reason many companies have left the business in the last two decades.

Another reason is that vaccines simply aren't very profitable, especially flu vaccine, which must be made fresh every winter to keep up with newly circulating strains. Ironically, although there have been three shortages since 2000 and supplies are strained again this year, in most years manufacturers throw away millions of unused flu shots.

"We cannot handle the threats we face today with a broken flu vaccine system," said Sen. Hillary Rodham Clinton, D-N.Y.., who with Sen. Pat Roberts, R-Kan., introduced legislation Thursday that would, among other things, financially guarantee a market in return for more vaccine production.

This month, vaccine maker Sanofi-Pasteur (search) begins the first mass production of a new vaccine that promises to protect against bird flu, producing $100 million worth of inoculations for a government stockpile.

But it would take months to create a new vaccine from scratch if a different strain of bird flu than today's known as H5N1 (search) emerges. Even if the vaccine works, Sanofi is producing enough to protect anywhere from 2 million to 20 million people — depending on how much must be put into each dose — and it's not clear when or where similar large stockpiles could be made.

The nation only has three main manufacturers of vaccine against the regular flu that circulates each winter.

A spokeswoman for one manufacturer expected at the meeting said a pandemic will transcend those issues.

"When you're actually in a pandemic situation, it's all hands to the wheel," said Nancy Pekarek, spokeswoman for GlaxoSmithKline, which hopes to begin testing its experimental bird flu vaccine in people next year.

Scientists have been warning for two years that bird flu in Southeast Asia is growing more ominous and that the United States must prepare.

Senior administration officials met Thursday with representatives from some 80 countries to compile an account of what is being done globally to prevent a pandemic, and to determine where improvements are needed.

Health and Human Services Secretary Mike Leavitt told the foreign health officials that preventing a pandemic would require a network of countries working together.

And he said though a pandemic may be avoided this year, or next year, there eventually will be one, as there was in 1918, 1957 and 1968.

"We need to be ready," Leavitt said.