"Flu remains a significant public health challenge, and mFLUSIVA provides an important new option for America's seniors," Moderna Chief Executive Officer Stéphane Bancel said in a statement. In that study, known as Fluent, mFLUSIVA demonstrated 26.6 percent relative vaccine efficacy compared with a licensed standard-dose influenza vaccine. Public health authorities continue to recommend annual vaccination for this population as the most effective way to reduce severe disease. The approval represents Moderna's fourth product cleared by the FDA and the first mRNA influenza vaccine authorized in the United States. Influenza remains a leading cause of vaccine-preventable illness among older adults.