** Shares of vaccine maker Moderna MRNA.O down 6.3% at $59.9 after gaining in six consecutive sessions leading up to a positive U.S. FDA advisory panel vote backing its flu vaccine

** "It wouldn't surprise me if profit taking has been occurring given the run-up in shares recently," William Blair analyst Myles Minter told Reuters

** MRNA shares rose 29.8% in six consecutive sessions of gains since June 10 through Friday

** The FDA panel on Thursday unanimously supported approval of Moderna's flu shot for adults aged 50 and older, saying its benefits outweigh risks across both 50–64 and 65+ age groups

** J.P.Morgan said the vaccine, mRNA-1010, and a potential COVID-flu combination shot could present an incremental opportunity but are unlikely to be "game-changing" for Moderna's long-term outlook

** Including session moves, stock has more than doubled YTD