Sanofi’s (SNY) high-dose flu vaccine for people above the age of 65 posted strong clinical results on Monday, paving the way for a label change that would tout the benefits of the higher dosage. 

The multi-year test with 30,000 patients displayed a “superior clinical benefit” of Fluzone High-Dose influenza virus vaccine compared with the standard dose of Fluzone, meeting its primary endpoints.

The high-dose vaccine was 24.2% more effective than just the single dose.

Sanfo Pasteur, the Paris-based drug company’s vaccine division, said it plans to submit the full clinical study to the U.S. Food and Drug Administration for review by early 2014. It is seeking a labeling change to reflect the higher dose in plus-65 patients.

“Older adults still have the highest rates of influenza-related hospitalization and death despite having high immunization rates," said John Shiver, senior vice president or R&D with Sanofi Pasteur. "This led Sanofi Pasteur to develop Fluzone High-Dose vaccine.”

While adults over the age of 65 comprise just 15% of the U.S. population, they account for 65% of the estimated 226,000 flu-related hospitalizations and a vast majority of the associated deaths.

Fluzone High-Dose vaccine, which was licensed in the U.S. by the FDA in December 2009 under an accelerated approval process to address the medical needs of older adults, contains 60 mcg of hemagglutinin antigen per strain of influenza virus, quadruple that of a standard dose.

Shares of Sanofi climbed about 2% to $51.41 in recent trade.

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