I work at an allergy/immunology clinic where most of our patients are on monthly immunotherapy injections for chronic allergies. Many of these patients are severely allergic to many things and are often very concerned about receiving a flu vaccine. For some reason I have had several patients request that they receive half a dose of a flu vaccine one week and the other half the next week in order to decrease the likelihood of a reaction. I am fairly new to this field and have never heard of this before. However, patients are telling me that the previous nurse administered their flu vaccine in this fashion for the past few years. CDC guidelines do not indicate giving a decreased dose for any reason. If an anaphylactic reaction has occurred in the past from a flu vaccine I know that that person is not a candidate for receiving the vaccine. Has anyone heard of this before? Please offer your thoughts.