** Shares of vaccine maker Moderna MRNA.O rise 5.9% to $51.69

** Co late on Wednesday reported results from a late-stage study that showed its mRNA-based seasonal flu vaccine worked better than conventional flu shots

** In the study, Moderna's flu shot was 26.6% more effective than an approved standard-dose flu shot from GSK GSK.L, exceeding the study's main goal

** The vaccine is currently under review by the U.S. FDA after the agency rejected the company's initial application

** FDA decision is expected by August 5

** Severe side effects were balanced between the two groups, occurring in 2.2% of those who received the mRNA shot and 1.9% with the standard dose vaccine, researchers reported

** Regulatory reviews for Moderna's flu shot are also underway in the EU, Canada and Australia

** Including session moves, stock up 65.5% YTD