Fall always brings flu season with it, but this year, the concern is raised due to the new Type A H1N1 virus. Just today, U.S. Secretary of Homeland Security Janet Napolitano, emphasized that the pandemic flu is likely to flare up soon after schools open in the fall, and well before a vaccine is available.

What's more, Napolitano indicated that vaccine supplies would be limited, at least early in the flu season. "There will be prioritization of vaccinations," she told USA TODAY.

A panel of experts advised the the Centers for Disease Control and Prevention that the first to be vaccinated should be pregnant women; parents and contacts of children younger than six months; health care workers; all children and young adults and all non-elderly adults with chronic medical conditions.

The flu strain causing the pandemic, a new strain-- Type A H1N1-- is especially unpredictable because it is genetically different from other known flu viruses. As a result, most people are defenseless against it, reports USA Today. This makes a vaccine even more important and critical to any prevention efforts.

There is much talk about the last severe flu pandemic, which occurred in 1918. But Napolitano said the anticipated flu epidemic this year is not likely to be as severe. In 1918, that flu killed at least 675,000 people in the United States and up to 50 million worldwide, reports USA Today. She pointed to the 1957 pandemic, which killed about 70,000 people in the United States and more than 1 million people worldwide, according to CDC. Seasonal flu kills about 36,000 Americans annually and hospitalizes 200,000 more, reports CDC.

The U.S. government has ordered 195 million doses of swine flu vaccine from five manufacturers, along with immune boosters called adjuvants that may be needed to ramp up the vaccine's potency. So far, the federal government has spent about $1 billion on pandemic flu vaccine, with an additional $350 million disbursed to states, territories and hospitals for more vaccine purchases and to build surge capacity in emergency rooms and intensive care units, reports USA Today.

Source: USA Today