Last fall, MedImmune Inc. launched an aggressive $25 million television and print ad campaign to convince consumers that its influenza vaccine, delivered through a squirt in the nose, was better than the traditional needle in the arm.The result? The drug once thought to be a potential blockbuster flopped. Only a fraction of the 4 million doses made were sold, and thousands ended up being distributed for free despite a harsh flu year.As Gaithersburg, Md.-based MedImmune prepares for FluMist’s second season on the market, it has dramatically scaled down and refocused its marketing plan for the nasal vaccine.