WASHINGTON -- A top federal health official said the nation's flu epidemic could get worse before it gets better.

Dr. Julie Gerberding, the director of the Centers for Disease Control and Prevention, said more states could be added to the list of states where the epidemic is now considered widespread. And she told NBC's "Today" show the nation will see a lot more flu before the epidemic subsides.

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Gerberding acknowledged that the current flu vaccine isn't as perfect as health officials would like because it wasn't designed to specifically treat the predominant flu virus strain attacking the nation. But she said it does treat a very similar strain.

On Friday, the nation's two vaccine manufacturers announced that their stocks of vaccine were gone.

In a typical year, 70 million to 75 million Americans receive a flu shot. This year, manufacturers produced about 83 million doses of flu vaccine. The United States has never used more than 80 million doses of flu vaccine in a season.

The CDC is assessing the status of the current flu vaccine supply in the United States. Most available flu vaccine supplies have been distributed to doctors, clinics, health departments and other providers -- which is not unusual for this time of year, the agency said.

"CDC is doing everything possible to assess the availability of flu vaccine to identify any locations that have supplies that may be able to be made available to locations that need vaccine," Gerberding said. "Some states have plans in place to redistribute vaccine supplies should that be needed."

Meanwhile, some areas are reporting vaccine shortages as people rush to get flu shots. Gerberding said people considered to be most at risk for the flu need to be "persistent" about getting vaccinated. They include people older than 65 and children between 6 months and 23 months old.

"Flu is very unpredictable. It is not uncommon for seasons to be quite different in their timing," said Dr. Keiji Fukuda, a CDC medical epidemiologist specializing in influenza. "We still don't know how this season will progress. It is too early to tell if the high level of activity that some parts of the country are experiencing will continue throughout our flu season."

U.S. Soldier Comes Home To Bury Child

A U.S. soldier returned home from Iraq to bury his only child, a young flu victim.

Alvin Beaumont said he and his wife are slowly trying to recover after their 14-month-old son, Jeremy, died Wednesday in Colorado. The death came after the child's health seemed to be improving slightly.

The toddler was the sixth child to die from the flu in Colorado.