The Bush administration, battered by criticism over its hurricane response, is getting the United States prepared for a possible travel ban and other restrictions in the event of a worldwide flu outbreak.

The president also said the United States must approve liability protection for the makers of lifesaving vaccines. He said the number of American vaccine manufacturers has plummeted because the industry has been hit with a flood of lawsuits.

Bush said no one knows when or where a deadly strain of flu will strike but "at some point we are likely to face another pandemic."

Can Kill People Who Are Young and Healthy

The president, in a speech at the National Institutes of Health, said the United States must be prepared to detect outbreaks anywhere in the world, stockpile vaccines and antiviral drugs and be ready to respond at the federal, state and local levels in the event a pandemic reaches the United States.

Bush outlined a strategy that would cost $7.1 billion (€5.9 billion) including:

$1 billion (€830 million) to stockpile more anti-viral drugs that lessen the severity of the flu symptoms;

Bush said a pandemic flu would be far more serious than the seasonal flu that makes hundreds of thousands of people sick ever year and sends people to their doctors for a flu shot. Unlike seasonal flu, pandemic flu can kill people who are young and healthy as well as those who are frail and sick, he said.

Fair Warning

In asking Congress for money to buy vaccine, Bush said the vaccine "would not be a perfect match to the pandemic flu because the pandemic strain would probably differ somewhat from the avian flu virus it grew from. But a vaccine against the current avian flu virus would likely offer some protection against a pandemic strain and possibly save many lives in the first critical months of an outbreak."

He also said the United States was increasing stockpiles of antiviral drugs, such as Tamiflu and Relenza. Such drugs cannot prevent people from catching the flu, but they can reduce the severity of the illness when taken within 48 hours of getting sick, he said.

"At this moment there is no pandemic influenza in the United States or the world, but if history is our guide there's reason to be concerned," Bush said. "In the last century, our country and the world have been hit by three influenza pandemics, and viruses from birds contributed to all of them."

He pointed out that the 1918 pandemic killed over a half million Americans and more than 20 million people across the globe. "One-third of the US population was infected, and life expectancy in our country was reduced by 13 years.

"The 1918 pandemic was followed by pandemics in 1957 and 1968, which killed tens of thousands of Americans and millions across the world," Bush said.

Bird flu has been documented in Asia and has spread to Europe but has not reached the United States, the president said. "Our country has been given fair warning of this danger to our homeland and time to prepare," he said.

Easy-to-Mutate Influenza Virus

Bush said the cornerstone of his strategy was to develop new technologies to produce new vaccines quickly. "If a pandemic strikes, our country must have a surge capacity in place that will allow us to bring a new vaccine online quickly and manufacture enough to immunize every American against the pandemic strain," Bush said.

The principal goal of Bush's plan, Health and Human Services Secretary Michael Leavitt said, "is the capacity for every American to have a vaccine in the case of a pandemic, no matter what the virus is."

"There is no reason to believe that in the next day or two or week or month that that's going to occur," Leavitt said on CBS's "The Early Show." But he added that "we do need to be ready in case it begins to mutate into a human transmissable disease."

Pandemics strike when the easy-to-mutate influenza virus shifts to a strain that people have never experienced before, something that has happened three times in the last century. While it is impossible to say when the next super-flu will strike, concern is growing that the bird flu strain known as H5N1 could trigger one if it mutates to start spreading easily among people. Since 2003, at least 62 people in Southeast Asia have died from H5N1; most regularly handled poultry.

The US strategy starts with attempting to spot an outbreak abroad early and working o contain it before it reaches the United States.

Today, most of the world's vaccine against regular winter flu is manufactured in factories in Europe.

Associated Press Writer Nedra Pickler contributed to this report.