BACKGROUND AND METHODS The role of immunoglobulin (Ig) E in immunity against influenza A H1N1 has not been studied. Total serum IgE and specific IgE and IgG anti-H1N1 virus responses were studied in children and adults (n = 2) who received influenza virus vaccination (Flumist(®) or Fluzone(®) ) in autumn 2008 and 2009, and then subsequently became infected with the H1N1 virus in spring 2009. Tw...