Updated

Vaccine maker Sanofi Aventis asked U.S. regulators on Monday to approve a new flu vaccine that uses a short, thin needle.

Sanofi says 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.

The company said the U.S. Food and Drug Administration had accepted the application and it hoped the agency would decide whether to approve it by early next year. The vaccine is approved for use in Europe.

"We believe that Fluzone Intradermal Vaccine could be an important tool in increasing adult immunization rates due to its ease of use for health-care providers and the high level of interest expressed by patients for this immunization option," Wayne Pisano, president and chief executive officer of the company's Sanofi Pasteur vaccine unit, said in a statement.

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.

Sanofi's short needle approach is called an intradermal vaccine. Many studies have shown that delivering flu vaccine into the skin activates specialized immune system cells called dendritic cells that help protect against infectious disease.

U.S. officials are recommending this year that all Americans over the age of six months receive a flu vaccine. The pandemic of H1N1 swine flu is over but the virus is still circulating, as are other strains of flu, and people need a fresh vaccine every year.

The United States has contracted with five companies to make influenza immunizations for the U.S. market -- Novartis, Sanofi, CSL, AstraZeneca unit MedImmune and GlaxoSmithKline. MedImmune's vaccine is needle-free and delivered by sprayer.

Vaccines that use less antigen may end up being less expensive. They can also help stretch the supply -- something that would have been helpful last year when companies struggled to make enough H1N1 vaccine fast enough.

Most of the vaccines ended up arriving after the first waves of the pandemic had passed.