WASHINGTON (AP) - A super-flu could kill up to 1.9 million Americans, according to a draft of the government's plan to fight a worldwide epidemic.

Officials are rewriting that plan to designate not just who cares for the sick but who will keep the country running amid the chaos, said an influenza specialist who is advising the government on those decisions.

”How do you provide food, water ... basic security for the population?“ asked Michael Osterholm of the University of Minnesota, a government adviser who has a copy of the draft plan and described it for The Associated Press.

”This is a much more comprehensive view than has previously been detailed,“ he said in an interview Saturday.

The Bush administration has spent the last year updating its plan for how to fight the next flu pandemic. While it is impossible to say when one will strike, the fear is that the bird flu in Asia could trigger one if it mutates to start spreading easily among people.

A recent draft of the plan, first reported Saturday by The New York Times, models what might happen based on the last century's three pandemics.

In a best-case scenario, about 200,000 people might die.

But if the next pandemic resembles the birdlike 1918 Spanish flu, as many as 1.9 million could die, Osterholm said. Millions more would be ill, overwhelming hospitals.

”You plan for the worst-case scenario,“ he said. ”If it's less than that, thank God.“

The government has on hand enough of the anti-flu drug Tamiflu to treat 4.3 million people. Manufacturing of $100 million worth of a bird flu vaccine just began.

The draft makes clear that tens of millions more doses of each would be needed. That is far more than the world has the capacity to manufacture quickly.

To finish that draft plan, federal health officials for several weeks have been role-playing what would happen if a super-flu struck now - not next year, after more medicines and vaccines have been stockpiled.

The strategy, Osterholm said, is, ”Don't emphasize what you can buy, emphasize what you can get your hands on. If it happens tonight, how do you deal with order?“

For example, health workers would need to wear special masks, known as N-95 masks, to prevent infection while treating patients. Two U.S. companies produce 90 percent of the world's supply and ”we'll run out overnight,“ Osterholm said.

Also being considered is the possibility that Tamiflu will not be powerful enough to treat someone already sick, but could protect against illness if given beforehand. So who would get the 4.3 million doses?

Health and Human Services Secretary Mike Leavitt recently met with Cabinet secretaries to get other federal agencies to determine their role in stemming rioting at vaccine clinics; when to close schools; how to keep gasoline, electricity, food and water supplies running; and how to manage the economic fallout.

State health officers are being asked for input, Osterholm said.

”The HHS plan is going to be the foundation of a larger government-wide plan,“ said Leavitt's spokeswoman, Christina Pearson. ”Beyond health care, there are issues with banks and schools, and that states and other place have to have their own plans.“

Democrats have criticized the administration for not having a plan.

Sen. Tom Harkin, an Iowa Democrat, said in a statement Saturday that time for action was short.

”Having a plan on paper does nothing to protect us,“ Harkin said while urging the administration to work with Congress on implementing protections against a pandemic. ”Next month is too late. The United States is woefully unprepared for this, and we must get started immediately.“