Seven states reported influenza cases for the week ended Oct. 9, the Centers for Disease Control and Prevention said in its first report of the season, after almost half the U.S. supply of vaccine was cut off.

California, Florida, New York, Pennsylvania and Texas, which have large numbers of seniors with a high risk of flu complications, reported scattered cases, according to the CDC Web site. Michigan and Utah also said they had virus activity.

``This is absolutely within the range of what we would expect for this time of year,´´ David Daigle, a CDC spokesman, said in a telephone interview. ``Last year was a bit of an exception, we had that early start, and this year is more of what we would expect.´´

U.K. regulators shut down Chiron´s Fluvirin plant in Liverpool, England, this month because of contamination. The Emeryville, California-based company had agreed to send about 50 million doses to the U.S. About 36,000 Americans die each year and 200,000 are hospitalized because of the flu, the CDC said.

Chiron shares rose 2 cents to $32.49 at 1:35 p.m. in Nasdaq Stock Market composite trading. They had dropped 29 percent since the announcement that Chiron´s flu-vaccine license was suspended in the U.K.

The 2000 census counted more than 35 million people over age 65, 12.4 percent of the U.S. population.

Second Supplier

The CDC is working with Sanofi-Aventis SA, the only other U.S.-approved supplier of flu shots, to get the vaccine to high- risk patients and will release guidelines for doctors to prevent and treat the disease with Roche Holding AG´s Tamiflu and other antiviral drugs.

U.S. Food and Drug Administration Acting Commissioner Lester Crawford Friday confirmed a U.K. health agency´s Oct. 5 finding that shots at Chiron´s Liverpool plant were unusable because their sterility couldn´t be verified. The FDA is testing some doses Chiron already had sent to the U.S. for safety.

Some lots of Fluvirin vaccine were contaminated with bacteria called serratia marascens, Crawford said. The germ can cause infection of the lungs, urinary tract and other tissues.

Congress and the U.S. Securities and Exchange Commission are investigating the Chiron plant´s closure.

``The company is committed to resolving the concerns raised by regulatory authorities in the United Kingdom and the United States,´´ Chiron said in a statement released Oct. 15. The company disclosed that some of vaccine was contaminated Aug. 26.

Gaithersburg, Maryland-based MedImmune Inc. plans to make about 2 million doses of its FluMist inhaled vaccine this year. It´s approved only for healthy people from 5 to 49 years old.

MedImmune shares gained $1.35, or 5 percent, to $27.67 in Nasdaq Stock Market composite trading.