The U.S. Food and Drug Administration has appoved Medimmune's FluMist, the first influenza vaccine intended to be sprayed into the nose instead of injected into the arm, and it is expected to be available in time for this years flu season. Doctors hope that the inhaled vaccine-which is approved for those between the ages of five and 49 years, a population that tends to avoid the flu shot-will increase the number of healthy people who get vaccinated and also free up the supply of the injected vaccine. The new vaccine is expected to cost $46 per dose, and while Medimmune will only produce up to 6 million doses this year due to manufacturing constraints, analysts think that the company will be able to sell them all. The agency has not approved FluMist for those with respiratory diseases or asthma, and because it contains a diluted live virus, it could be risky for people with weakened immune systems. Medimmune is planning to conduct more tests so it can get the vaccine approved for the elderly and the very young.