The flu season (search) in the United States is off to a slow start, with only Delaware and New York reporting significant outbreaks — a relief to government health authorities, given the U.S. vaccine shortage.

Even so, the "widespread" flu activity in Delaware — the first state to be classified at the nation's highest flu level — is a little misleading. The state meets the designation because confirmed cases of the flu had been found in every county of that state. But the state has only three counties — and six cases in all.

"From the data that we see, things haven't really taken off — it's continued flu activity at low levels in a lot of places," said Lynnette Brammer, a flu epidemiologist at the Centers for Disease Control and Prevention (search). "It looks like New York, the mid-Atlantic area is where things are starting to pick up, but it's early. At this point, you can't tell how the season's going to progress."

Nursing home outbreaks in New York prompted the CDC to classify that state as having "regional" flu activity — one step below "widespread." Most other states listed "sporadic" flu cases.

Although the flu season can begin as early as October and last through April, most flu seasons do not peak until January.

Health authorities have said the slow start has been a relief, because it has given them extra time to warn people to prepare for the flu in a year that has been marked by a severe flu-shot shortage.

Health officials had planned this season on having more than 100 million doses of the vaccine, the biggest supply ever. But last month, flu-shot maker Chiron Corp. (search) announced it could not ship its 48 million doses after British health officials suspended the maker's license because of contamination at a Liverpool plant.

As a result, there is not enough vaccine available for Americans at the highest risk for severe complications or death. Those include the elderly, babies, pregnant women and anyone with chronic heart or lung disease.

Only 61 million doses are available this season, including a nasal vaccine only for healthy people. But 98 million people, including 9 million children, need the vaccine, the CDC said.

Each year, the flu hospitalizes about 200,000 people and kills on average 36,000 people in the United States, according to the CDC.