“Financial Disclosure: Dr Keitel has received research support from Protein Sciences Inc and Novartis Vaccines. Dr Nichol has served as a consultant for the influenza vaccine manufacturers sanofi pasteur, GlaxoSmithKline Biologicals, CSL Biotherapies, Novartis, and MedImmune and has received research funding from sanofi pasteur and GlaxoSmithKline Biologicals. Dr Treanor has received research support from Protein Sciences, Merck, Wyeth, GlaxoSmithKline, Antigen Express, Mercia Pharma, VaxInnate, Ligocyte, Sanofi, and CSL Biotherapies; has served as a consultant/scientific advisory board member for AlphaVax, Epimmune, Dynavax, Immune Targeting Systems, Pulmatrix, Powdermed, PaxVax, and Toyama; and has served as a Data Safety Monitoring Board member for Medimmune and Novavax.”