I just stumbled on this PubMed case of a UC patient flaring after a flu shot. Not to cause alarm but, between Imuran and UC, I am never too sure about
flu shots (besides which, alot of the data on their effectiveness in preventing the flu is ambiguous- some studies claim big benefits, others none at all).
http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&Cmd=ShowDetailView&TermToSearch=17525521&ordinalpos=3&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum