Close up image of a caretaker helping older woman walk

The U.S. Food and Drug Administration late last month approved a high-dose influenza vaccine for people 65 and older.

The vaccine, which is produced by Sanofi Pasteur, the vaccine unit of Sanofi-Aventis DA, uses a higher dose to produce a stronger immune response and better protect older adults against the seasonal flu. It will be available in the fall of 2010 in advance of the next flu season.

Studies showed a stronger immune response with this vaccine compared with the original Fluzone. The company must further study the vaccine to verify that the high-dose version decreases seasonal flu after vaccination, the FDA said.