French drugmaker Sanofi Aventis said on Tuesday it had won U.S. approval to market its Fluzone Intradermal vaccine for adults, allowing for flu injections with a very fine needle.

Sanofi has said that the new vaccine, developed with syringe maker Becton Dickinson, may hurt less than standard vaccines, does a better job of stimulating protection against influenza, and requires less of the active ingredient.

Most adult flu vaccines are given using a needle 1 inch to 1.5 inches (25 mm to 40 mm) long that goes into muscle tissue.
Sanofi's new needle is one-tenth that long, just 1.5 mm, and the vaccine uses one-fifth the usual amount of the active ingredient, called antigen.

The Fluzone Intradermal vaccine will be available to healthcare providers in the U.S. for the 2011-2012 flu season, Sanofi said in a statement.