Across the country, families are rising at the crack of dawn, waiting up to three hours in line, and some schools are closing down in order to protect against the growing flu outbreak.

INFLUENZA Flu: Prevention | Treatment Survey: Did You Get Vaccinated? Slideshow: Fight Flu At Work FROM OUR PARTNERS Symptoms: Is It Flu? Prevention: Stop The Flu More: Kids And The Flu

The heightened concern comes after the number of children in the United States who have died from the flu jumped from 11 to at least 20, officials say. There are now widespread outbreaks in 24 states.

This flu season seems to be worse for children, although the government said it's unable to say how many children typically die of the flu each year. Flu and its complications are the sixth-leading cause of death in children under 4.

But national health officials say most people have little reason to fear.

Dr. Julie Gerberding said people shouldn't panic or assume the worst as they prepare for the growing flu outbreak.

Gerberding, the director of the Centers for Disease Control and Prevention, told NBC's "Today" show that the nation's remaining flu vaccine is on its way to clinics and hospitals in every state. After that, Gerberding said, the CDC will try to contact European manufacturers of vaccines.

But she also noted that many people have options other than the flu shots. Those between the ages of 5 and 49 can use FluMist, a nasal vaccine that more expensive than a traditional vaccination, but is more widely available.

And Gerberding also stressed that the vast majority of people who contract the flu will face normal symptoms from which they can easily recover.

But officials stress that those with health risks -- including the very young, the very old and the sick -- should try to get a shot if possible.

The town of Malad, Idaho, has virtually shut down. So many of the town's 2,000 residents have come down with the flu that area churches have canceled services, Christmas programs have been postponed and even Santa's visit with the children is getting pushed back.

Stories like that are making people nervous across the nation -- even if an area hasn't been hit by the flu. People aren't taking chances. Instead, they're racing to get vaccine shots.

That includes Florida, where so far, the flu is not considered widespread. Even so, up to 400 people were waiting at a shopping mall near Orlando Friday morning for the remaining free flu shots there. They came out of concern for their health, but ironically had to spend hours shivering in the cold to get some vaccine.

Amy Goodwin of the Virginia Hospital Center in Arlington, Va., said at one point, a line of about a dozen people ballooned to about 100 within minutes. The hospital started the day with 300 doses of vaccine, and by noon, it was out.

Doctors in Texas say there is a shortage of booster shots to keep young children protected. But they say the shortage should not result in a second wave of flu outbreaks.

Hundreds of people lined up Friday morning at the Greenville, S.C., County Health Department for their last 400 flu shots.

Some people said they camped out overnight to be in line, and at least one family came from Charlotte, N.C., because they hadn't been able to obtain shots there.

Other clinics have simply run out of vaccine or are turning people away.

In Colchester, Conn., one school threw in the towel and canceled classes after more than one-third of the student body called in sick.

Madison Junior High in Mansfield, Ohio, has closed as well. The school's principal said it was the first time the flu has shut down his school.

Mission Hospitals in Asheville, N.C., is restricting people from visiting patients to keep the flu from spreading. Another state hospital is discouraging visitors entirely.

Health officials urge people who are sick to stay home to avoid spreading the flu -- and to protect their own health.

"If you push yourself out the door to go to work, you can do more serious damage, which is pneumonia," said Dr. Ingrid Buxton, a professor of science at Marquette University in Milwaukee.

Doctors nationwide report increased numbers of flu patients -- but there is some good news. In Colorado, state health officials say the outbreak has peaked in the Denver area.

The government says more flu vaccine will be on the way soon.

They say another 100,000 doses of adult vaccine should be ready to go out to state health departments this weekend. Another 150,000 shots for children are not due to arrive until next month.

Flu Remedies Selling Swiftly

The flu outbreak that's swept through much of the country has created a run on cold and flu medications.

Drug stores and online companies are reporting brisk sales of over-the-counter remedies and prescription drugs in recent weeks.

Products like Nyquil, Robitussin, and Tylenol are flying off the shelves.

Drugstore.com said its sales have jumped 46 percent in the past five weeks when compared with this time a year ago.

Both Walgreen Drugs and Wal-Mart are reporting a rise in flu drug sales.

Some stores report intermittent shortages of certain products.

In New York, Ben's Best Kosher Deli said its traditional "cold and flu baskets" are selling well. They contain chicken soup, tissues and a mug that says "Jewish penicillin."

Two Insurance Companies To Cover FluMist

Sales of the inhaled flu vaccine may have gotten a shot in the arm from two major insurance companies.

Aetna and Cigna Healthcare say they will extend flu vaccine coverage to include FluMist due to the nationwide shortage of flu shots. The two companies provide healthcare coverage for about 25 million people.

Several regional insurance companies across the country also are now covering FluMist. Most insurance companies did not cover the drug at the outset of this year's flu season.

Sales of FluMist have been slow, in large part because of its high price.

FluMist is squirted into the nose. It is made from a weakened, live flu virus and may only be given to healthy people between the ages of 5 and 49.

Experts Say Worldwide Pandemic Inevitable In Future

Experts say it's just a matter of time.

They say a worldwide flu pandemic will eventually come again -- and one doctor says when it does, it will be "horrific" for the United States.

There have been three flu pandemics in the past 100 years, including the Spanish flu of 1918 and 1919, which killed an estimated 20 million people worldwide. The last one came in 1968.

The World Health Organization predicts the next pandemic will kill up to 650,000 people.

Doctors say there's no way to predict when the next one will hit.

They say flu shots won't get the job done against a pandemic, because virus strains develop quickly and unexpectedly, and there's not enough time to get a vaccine to fight them.

Experts say pandemics are potentially sparked by a new strain of virus that humans have no natural resistance to. That's opposed to ordinary outbreaks like this year's, which are somewhat related to earlier viruses against which people have some protection.