French drugmaker Sanofi SA said the U.S. Food and Drug Administration had approved its four-strain influenza vaccine, which is meant to provide better protection from infection than traditional three-strain flu vaccines.The Fluzone Quadrivalent vaccine is licensed for adults, adolescents and children 6 months and older, and will be available in the upcoming 2013-2014 flu season, the company said on Monday.The 2013 influenza season will be the first when quadrivalent influenza vaccines will be available in the United States. Read the full story.