The flu shot is actually given with a needle. Flu mist is a vaccine that is given through the nose and is a mist. Many people really like the mist because they do not have to deal with needles. There are certain people though that cannot receive the flumist.
The list includes
•children younger than age 2
•adults older than 50 years old
•children with medical conditions, such as asthma or reactive airway disease, diabetes, chronic heart disease, chronic lung disease or a weakened immune system
•children younger than age 5 who have had problems with recurrent wheezing
•children who are taking aspirin
•teens who are pregnant
From the site http://pediatrics.about.com/od/flushots/a/808_mistorshot.htm
I hope this helps. Both of the websites listed below should given you a more detail answer.