(Update in last paragraph with list of companies making the flu vaccine.) By Shayndi Raice Of DOW JONES NEWSWIRES WASHINGTON (Dow Jones)--The U.S. Food and Drug Administration announced Friday it has approved vaccines for the 2010-2011 flu season. The latest flu vaccine will prevent against three strains of influenza, including the H1N1 virus, or swine flu, that caused last year's pandemic. Karen Midthun, acting director of the FDA's center for biologics evaluation and research, said the best way to protect against the flu is to get vaccinated annually. "The availability of a new seasonal influenza vaccine each year is an important tool in the prevention of influenza related illnesses and death," she added. Because H1N1 developed after the flu vaccine was produced, a separate vaccine to address swine flu was needed. The FDA's approval means that only one vaccine will be required for all strains of influenza. Companies that will be producing a version of the vaccine include CSL Limited (CSL), Novartis Vaccines and Diagnostics (NOVN), GlaxoSmithKline Biologicals (GSK), ID Biomedical Corporation, MedImmune Vaccines Inc., and Sanofi Pasteur Inc. (SNY). -By Shayndi Raice, Dow Jones Newswires; 202-862-9291; shayndi.raice@dowjones.com (END) Dow Jones Newswires July 30, 2010 14:57 ET (18:57 GMT)