In fact, in two separate published studies from our laboratory using monovalent inactivated IIVs, we have found vaccine-induced expansion of CD4 T cells specific for influenza M1 and NP epitopes in addition to HA-derived epitopes13,14 in agreement with the studies by other groups.8–12 The consequences of the responses to influenza viral epitopes other than HA is not known at this time but is important to consider. The gene discussed is CD4; the disease is influenza.